UC-NRLF 


*B    301    531 


LIBRARY 

OF  THE 

University  of  California. 

Class 


Digitized  by  the  Internet  Archive 

in  2008  with  funding  from 

Microsoft  Corporation 


http://www.archive.org/details/elementsofagricuOOmcbrrich 


Elements  of  Agriculture 


FOR  USE  IN  SCHOOLS 


JAMES  BOLTON   llcBRYDE,  C.  E. 

VIRGINIA   POLYTECHNIC  INSTITUTE 


RICHMOND,  VA. 

A  F.  JOHNSON  PUBLISHING  CO. 

IQOI 


M 


r 


GENERAL 


Copyright,  1901,  by 
James  Bolton  McBryde 


All  rights  reserved. 


9-07— H.  P. 


PREFACE 


The  pressing  need  of  -some  agricultural  instruction  in  our 
public  schools  is  generally  admitted  by  all  who  have  given  due 
thought  to  the  subject.  Especially  is  this  true  in  the  Southern 
States,  where  the  gnat  majority  of  the  population  is  engaged 
in  agricultural  puiMiit>,  and  where  comparatively  few  students 
lioin  Hi,-  rural  district-  Bod  their  way  to  college.  According 
t<»  the  census  of  1900,  the  total  population  of  the  Southern 
States  is  about  23,000,000.  Of  this  number  the  rural  popula- 
tion makes  up  fully  75  per  cent  or  more;  in  other  words,  about 
17,000,000.  The  total  number  of  persons  enrolled  during  the 
session  of  1898- '99,  as  students  of  agriculture  in  the  land-grant 
colleges  of  the  South  was  1,777,  or  about  .0001  per  cent  of  the 
agricultural  population.  The  number  of  persons  receiving 
agricultural  inst  met ion  outside  of  these  colleges  is  so  small 
as  not  materially  to  affect  the  result,  and  it  is  safe  to  say 
that  of  the  agricultural  population  of  the  South  not  more  than 
one  penOB  in  10,000  receives  any  schooling  in  agriculture. 
We  ha\c,  then,  the  amazing  spectacle  of  an  agricultural  com- 
munity that  is  spending  annually  for  its  schools  and  colleges 
about  $35,000,000,  and  yet  giving  instruction  in  agriculture  to 
only  one  ptfVoB  in  every   16,000  of  the  agricultural  population. 

That  there  are  still  great  difficulties  in  the  way  of  the  work 
Miiltural  education  is  freely  admitted.  The  want  of 
thoroughly  trained  teacher-,  the  Med  of  more  and  better  appa- 
ratus and  text  hooks,  and  the  want  of  appreciation  on  the  part 
Of  the  general  public,  are  great  barriers  in  the  way  of  progress. 
But  these  barriers  must  and  will  in  time  be  removed,  teachers 
will  be  better  trained,  more  and  better  apparatus  will  be  pro- 
vided, better  text  books  will  be  written,  and  when  all  this 
comes  to  pass  the  public  will  soon  learn  to  appreciate  this  line 
of  educational  effort. 

166756 


6  PREFACE 

The  object  in  preparing  this  little  book  has  been  to  present 
in  simple  language  some  of  the  more  important  principles  of 
agriculture,  with  the  hope  that  as  herein  set  forth  they  may 
serve  to  stimulate  in  the  pupil  a  desire  for  further  informa- 
tion on  the  subject.  Details  have  been  as  far  as  possible 
avoided,  for  to  attempt  to  load  the  pupil's  mind  with  a  mass 
of  details  would  be  to  defeat  at  the  start  the  primary  object 
of  the  book.  It  must  be  borne  in  mind  that  within  the  limits 
of  an  ordinary  volume  it  is  impossible  to  present  more  than  a 
very  brief  outline  of  the  first  principles  of  agriculture.  Many 
topics  must  be  omitted  entirely  and  others  touched  upon  very 
briefly.  .  It  is  hoped,  however,  that  these  first  principles  may 
provide  the  student  with  a  ground-work  upon  which  to  build  a 
more  perfect  knowledge  of  agriculture. 

Teachers  should,  whenever  possible,  supplement  and  illus- 
trate the  text  by  examples  drawn  from  their  own  observations 
and  experience,  and  should  encourage  pupils  to  observe  and 
investigate  for  themselves. 

For  revising  my  manuscript  and  for  many  valuable  sugges- 
tions, my  thanks  are  due  Dr.  J.  M.  McBryde,  of  the  Virginia 
Polytechnic  Institute;  Prof.  T.  C.  Karns,  of  Tennessee;  Mr. 
J.  F.  Jackson,  of  the  Southern  Planter;  Prof.  D.  O.  Nourse,  of 
the  Virginia  Polytechnic  Institute;  Mr.  David  Cloyd,  of 
Dublin,  Va. ;  Prof.  C.  E.  Vawter,  of  the  Miller  Manual  School ; 
Dr.  J.  M.  McBryde,  Jr„  of  Hollins  Institute,  and  Dr.  F.  D, 
Wilson,  of  the  Virginia  Polytechnic  Institute.  For  the  illus- 
trations I  am  indebted  to  Dr.  Chas.  N.  McBryde,  of  the  Vir- 
ginia Polytechnic  Institute. 

J.  B.  McB. 

Virginia  Polytechnic  Institute,  Blacksburg,  Fa, 


CONTENTS 


II  \ri  >   i: 

r  \KT  I— Cum  ate 

PAOK 

1. 

Bulfgfct,       ..... 

0 

11. 

Sunlight    (Continued), 

14 

III. 

Rain,            -                          -             -             - 

18 

IV. 

The    Atmosphcr. 

23 

v. 

Tin-  Atmosphere  (Ooatinned), 
PAST  II— Plants 

28 

VI. 

Plant-  ami  Their  Seed, 

33 

\  II. 

Part-   of  a    Plant.    -               - 

38 

VIM. 

Composition   of   Plants, 

45 

IV 

(oinpo-ition  of  Plants    (Continued), 

50 

V 

The  Pood  the  Plant   Tskei  from  the  Soil, 

55 

XI. 

Ihr  Pood  tin-  Plant  Takes  from  the  Air, 

60 

Ml. 

Don    Plants  Grow, 

PAPT  III— Soils 

63 

Mil 

How   Soil-    ;iiv    Ma-lr, 

67 

\l\ 

Clarification   of  Soils, 

72 

W 

CompooitJoa  of  BoHo, 

78 

\\  1 

Composition   of   Bofll    I  Cont  inue.l  i , 

83 

\\  II 

Water   in    S..H-,        - 

88 

WIN. 

Niii'V-'ti    in   the   Soil, 

94 

\l  | 

How  Soils  Looe  Water, 

100 

\\ 

How  Soils  Lose  KltiqgOB, 

106 

\\l. 

How    Sc.il-    Lose    Mineral    Matter, 

110 

Wll 

Cultivation  of  Soils, 

117 

Will. 

Cultivation   of                      utinued), 
P  \i:T  H       Mam  res 

122 

\\l\ 

itiOB    "i     Manm 

128 

\\\ 

iii.rii.il     I'.-il  ili/crs. 

ita 

\\\  1 

Mi.ivi.l     Fertilizers    (Continued),      • 

138 

\\\  11. 

Use  of  Manures,     .... 
(7) 

145 

CONTENTS 


CHAPTER  PART  V-FARM  CROPS 

XXVIII.     Seed   Testing,          ....  151 
XXIX.     Classification  of  Crops:    Cereal  and  Fod- 
der Crops,          -             -             -            -  157 
XXX.     Fodder  Crops  and  Pastures,          -             -  164 
XXXI.     Root   and    Tuber    Crops:      Miscellaneous 

Crops,     -  -  -  -  -  172 

XXXII.     Rotation   of  Crops,  -  -  177 

PART  VI — Animal  Production 

XXXIII.  Composition  of  Animals,  -  -  -  181 

XXXIV.  Food,  Work,  and  Growth  of  Animals,      -  186 
XXXV.     Care  of  Animals,    -                           -  190 

XXXVI.     Feeding  of  Animals,  -  -  -  195 

XXXVII.     Stock  Food,  ....  198 

XXXVIII.     Digestibility  of  Stock  Foods,         -  -  204 

XXXIX.     Calculating  Rations  for  Animals,  -  208 

XL.     Selecting  Stock  Foods,       -  -  214 


PART  VII — Miscellaneous  Topics 

XLI.     Birds, 218 

XLII.     Insectivorous    Birds,  -  -  -  222 

XLIII.     Seed-Eating    Birds,  -  -  -  228 

XLIV.     Birds  of  Prey,         -  -  -  -  232 

XLV.     Forestry,      -  -  -      .      -  238 

XLVI.     Roads,  -  -  -  243 

Appendix 

Tables,  -  -  -  251 

Index, 261 


(. 
UN!  *) 


Elements  of  Agriculture 


PART  I.-Climatb 


CHAPTER  I.— Sunlight 

1.  Sunlight  the  Source  of  all  Life.— Sunlight,  water 
and  air,  all  three  so  important  to  our  health  and  happi- 
ness, are  equally  necessary  to  the  health  and  growth  of 
plants.  Children  raised  in  the  foul,  dark  slums  of  a 
city  are  apt  to  be  sickly  both  in  mind  and  body.  The 
strongest  alone  survive,  and  they  too  often  grow  up  as 
full  of  evil  as  their  surrounding.  Poor  children  !  Their 
jpeni  between  the  dull  brick  walls  of  the  city, 
with  seldom  ■  glimpse  of  the  country  with  its  glorious 
sunlight,  it-  birdi  and  its  i!  Sow  can  they  grow 

up  t<>  lie  perfect  men  and  women?  No  more  can  the 
little  plant  struggling  along  in  some  (lark  corner  grow 
up  to  its  full  lxauty  and  power. 

The  light  and  heal  wliieb  come  to  us  from  the  sun  in 
the  form  of  Bonahine  ai  resy  child  should  know, 

rarCCS  of  all  life  on  this  earth;  hence  to  sunshine 
dture  ow  <    little  is  yet 

known  of  tbis  quickeiier  of  life.  It  is  known  that  sun- 
shine produces  both  heat  and  light,  and  that  the  two 
may  be  separated,  but  much  remains  to  be  discovered  in 
regard  to  it;  and  men  now  unknown  may  make  their 
names  immortal  by  telling  the  world  more  about  it. 


10  ELEMENTS  OF  AGRICULTURE 

2.  Heat. — A  stone  thrown  into  a  quiet  pool  of  water 
produces  waves,  which  move  rapidly  from  the  place 
where  the  stone  struck  to  the  shore,  where,  striking 
against  the  grains  of  sand  and  soil  particles,  they  shake 
them  about.  When  sunshine  comes  to  the  earth  from 
the  -sun,  it  moves  in  waves  just  as  perfect  as  those  pro- 
duced in  the  water.  But  the  waves  of  sunshine  travel 
very  much  faster  than  the  waves  of  water,  and  are  so 
very  small  that  they  cannot  be  seen.  Now,  these  waves 
of  sunshine  coming  from  the  sun  strike  against  the 
surface  of  the  earth  and  shake  up  its  very  small  par- 
ticles, or  molecules,  as  they  should  be  called,  much  as 
the  waves  in  the  pool  of  water  shake  up  the  particles  of 
soil  on  the  shore.  From  the  motion  produced  among  its 
surface  molecules  the  earth  becomes  warmed.  If  a  crowd 
of  children  are  all.  running  about  very  fast  and  bumping 
into  one  another  they  soon  become  quite  warm  from 
the  violent  exercise.  So  with  the  small  particles  or 
molecules  against  which  the  sun's  heat  strikes;  they 
become  much  excited,  move  about  very  rapidly,  bump 
into  one  another,  and  are  thus  warmed. 

3.  Steam. — When  a  kettle  of  water  is  put  over  a  fire 
to  boil,  the  little  heat  waves  from  the  fire,  which  are 
like  those  from  the  sun,  first  warm  up  the  kettle.  When 
the  kettle  becomes  warm  it  transfers  some  of  its  heat 
to  the  water,  and  so  motion  begins  among  the  molecules 
of  water.  This  motion  is  slow  at  first,  but  as  the  heat 
waves  from  the  fire  continue  to  strike  against  the  kettle, 
more  and  more  heat  passes  through  to  the  water,  and 


SUNLIGHT  11 

tin-  motion  of  its  molrnilo  Incomes  faster.  Soon  tin.* 
u.it.  r  begin  to  1  m Wl.lt-  and  boil  from  the  rapid  motion 
of  its  molecules.  Some  of  the  surface  molecules  from 
their  rmpid  motion  an-  thrown  ofT  from  the  boiling  water 
and  tloat  about  in  the  air  in  the  form  of  a  gas,  which  is 
en  1  led  STEAK. 

4.  Condensation. — If,  in  the  steam  from  ■  hoiling 
kettle,  Borne  i  old  objeaj  is  held  for  a  few  moments  drops 
Of  water  colled  <>n  it.  The  heated  molecules  which  make 
Op  the  steam  strike  against  the  cold  object  and  are 
cooled  otT.  become  quiet,  and  collect  in  drops  of  water. 

i  ttemn  is  said  to  OONDKHSB.  When  steam  rises 
from  boiling  water  into  the  air  above,  it  cools  off  and 
gathers  into  tine  drops  of  moisture,  which  make  up  the 
white  steam  to  be  seen  rising  from  hot  water.  Notice 
how  dense  and  white  the  steam  is  on  a  cold  day. 

5.  Evaporation. — When  heat  waves  from  the  sun 
strike  against  Ipdiei  of  water,  such  as  oceans,  lakes  and 

-.  they  etnas  rapid  motion  among  the  surface  mole- 
cules of  water:  this  motion  is  so  strong  at  times  that 
many  of  the  water  molecules  are  thrown  off  into  the 
air  above  as  they  were  from  the  kettle  of  boiling  water. 
This  change  Is  called  kwporation.  But  evaporation 
is  not  dependent  on  sunshine,  though  it  takes  place 
more  rapidly  under  its  influence.  Air  has  the  power  of 
taking  Up  water  li!  age,  and  like  the  sponge  can 

hold  only  a  certain  amount.  When  air  has  taken  up  all 
ri  hold,  it  is  said  to  be  saturated.  Then 
evaporation  ceases,  but  so  long  as  the  air  is  not  satu- 
rated evaporation  may  go  on.  A  bucket  of  water  placed 
in  a  room  protected  from  sunshine  gradually  evape- 


12  ELEMENTS  OF  AGRICULTURE 

rates,  and  so  long  as  fresh  air  is  admitted  to  the  room 
so  long  will  evaporation  take  place.  Wind  causes  rapid 
evaporation;  sweeping  across  bodies  of  water,  the  air 
takes  up  water  as  it  goes;  it  is  somewhat  like  passing  a 
dry  sponge  over  a  wet  slate.  Of  course,  the  water 
warmed  by  the  sun  does  not  actually  boil.  Water 
evaporates  when  it  is  warmed,  and  the  more  it  is  warmed 
the  more  rapidly  it  evaporates. 

6.  Mist,  Clouds. — Most  of  us  have  noticed  on  a  cool, 
frosty  morning,  when  the  sunshine  strikes  a  pond  or 
river,  how  it  steams  like  a  great  boiling  kettle  of  water. 
This  is  all  the  work  of  the  little  heat  waves  from  the 
sun.  They  evaporate  the  surface  water,  which,  rising 
into  the  cool  air,  is  condensed  into  tiny  drops  of  water, 
which  form  mist..  Mist,  then,  is  made  up  of  very  small 
drops  of  water.  Mist,  or  fog,  as  it  is  sometimes  called, 
rises  high  above  the  earth  and  gathers  into  what  we  call 

CLOUDS. 

7.  Rain. — Clouds  which  we  see  floating  about  in  the 
air  are  still  warm  from  the  sunshine  which  helped  to 
form  them.  When  they  come  in  contact  with  a  cold 
current  of  air,  or  a  cold  mountain  top,  they  lose  this 
heat  and  condense  to  drops  of  water,  which  being 
heavier  than  air  fall  as  rain.  The  cold  air  or  mountain 
top  acts  just  as  any  cold  body  would  if  held  in  a  cloud 
of  steam. 

8.  Hail,  Snow. — Sometimes  raindrops  are  caught  in 
very  cold  currents  of  air.  In  these  air  currents  they  are 
held  till  they  become  balls  of  ice,  in  which  form  they 
fall  as  hail.     When  the  air  becomes  sufficiently  cold, 


BtJNLlOJlt  1.1 

the  moisture  in  clouds  is  frozen  into  ice  crystals,  which 
fall  as  snow. 

Questions 

I  T«>  what  does  agriculture  owe  its  existence?  2.  What 
does  sunshine  bring  to  the  earth?  Can  tin*  two  be  separated? 
A.  H<o\  (liM-s  sunshini'  travel  to  us  from  Um  suh?  4.  It  \..u 
throw  a  stone  into  a  ijui.t  pool  of  water,  what  sort  of  motion 
is  started  on  the  surface  ol  Um  water'.'  f>.  Why  can't  we  see 
waves  of  sunshine?  6.  What  happens  when  waves  in  a  pohd 
ol  water  strike  tin-  shore":  7.  \\  liat  happens  when  w.i 
himfcfal  strike  Um  earth's  surface?  8.  When  sunshine  strikes 
bodies  of  water  what  happens?  9.  What  is  aieam?  10.  II  >\> 
are  nindropa  formed  1    n.  What  is  snow? 


14  ELEMENTS  OP  AGRICULTURE 


CHAPTER  II.— Sunlight 
(Continued) 

9.  Solids,  Liquids,  and  Gases.— The  changes  which 
water  goes  through  when  it  evaporates  to  form  cloudsj 
and  the  freezing  of  clouds  to  hail  or  snow,  show  that 
water  may  exist  in  three  different  forms:  first  as  a 
liquid,  second  as  a  gas,  and  third  as  a  solid.  Every- 
thing we  know  is  either  a  liquid,  solid,  or  gas.  Water 
may  be  easily  changed  from  one  form  to  another,  but 
many  substances  are  very  difficult  to  change.  Iron,  a 
solid,  when  heated  very  hot,  melts  to  a  liquid,  and  it 
may  even  be  heated  so  hot  that  it  becomes  a  gas.  Air, 
under  pressure,  has  been  liquefied  by  intense  cold,  and 
other  wonderful  changes  have  been  made.  As  a  rule, 
heat  causes  substances  to  expand  and  melt,  and  if  they 
are  heated  sufficiently  high  they  expand  still  more  and 
become  gases.  On  the  other  hand,  cold  causes  most  sub- 
stances to  contract  and  change  from  gases  to  liquids, 
and  from  liquids  to  solids.  This  expanding  and  con- 
tracting of  bodies  is  made  use  of  in  the  thermometer, 
which  is  a  tube  partly  filled  with  mercury  or  alcohol. 
All  of  the  air  is  carefully  taken  out  of  the  tube,  the 
mercury  is  then  put  in,  and  the  tube  sealed  up.  When 
the  mercury  is  heated  it  expands  and  rises  in  the  tube; 
when  it  cools  off  it  contracts  and  falls.  By  this  rising 
and  falling  in  the  tube  we  measure  the  intensity  of  heat 
or  cold. 


8DNLI0IIT  15 

10.  Winds. — The  heat  waves  from  the  sun  perform 
an  important  duty  in 'making  winds.  When  tin-  surface 
of  the  earth  is  w m rm«-.l  l»y  tin*  heat  waves  from  the  sun, 
it  in  turn  warm-  uj>  the  air  which  is  pressing  against  it 
Warm  air  rises,  and  oold  air,  which  is  heavier,  moves  in 
to  take  its  place.  Thus  the  air  ifl  I  on-tantly  moving 
■bout,  and  the  motion  is  ealhd  wind.  The  motion  of 
the  air  helps  to  keep  the  earth   from  beodttfag  too  hot 

1  air  rises  ami  takes  witji  it  a  quantity  of  heat 
from  the  earth;  colder  air  comes  in  its  place,  and  this 
in  it-  turn  is  warmed  up  and  carries  ofT  more  heat.  So 
changing  may  go  on  until  the  earth  is  cooled  oft 
Notice  the  air  near  a  itone  or  hrick  wall  some  hot  day 
and  Bee  the  waves  of  hot  air  rising.  When  a  fire  is  built 
on  a  hearth  it  first  heats  tin-  air.  which,  rising  up  the 
chimney,  camel  a  draught.  Winds  are  distrihut. 
rain;  moving  over  the  country  they  earn  with  them 
clondfl  of  moisture,  which,  vheo  condensed,  fall  as  rain. 
The  winds  from  th«  ocean  bring  in  to  the  land  great 
quantities  of  rain  cloud-. 

11.  Radiation. —  During  the  summer,  when  the  sun 
poors  down  greal  quantities  of  heat  day  after  day.  the 
eartli  thoroughly  warmed  up.  The  land  is 
wanned  by  the  sunshine,  ami  hodies  of  water  are 
wanned  even  more  thoroughly  than  the  soil.  Thus  the 
earth  is  storing  up  heat  in  hind  ami  water  for  use  at 
night  and  in  the  cold  winter.     At  [light,  when  the  <un 

has  set  and  the  inpplj  of  heat  waves  is  temporarily  shut 

ofT,  the  air  would  DeCODM  v.  r\  eokl  but  for  the  heat  th( 
earth  has  stored  during  the  day.  The  air  pressing 
against  the  earth  is  warmed  by  the  stored  heat,  and  thud 


I  6  ELEMENTS  OF  AGRICULTURE* 

prevented  from  becoming  intensely  cold.  When  the* 
earth  warms  up  the  air  it  is  said  to  radiate  its  heat. 
Radiation  means  that  a  warm  body  is  throwing  off  heat 
The  sun  radiates  heat;  a  hot  stove  or  fire  also  radiates 
heat;  The  earth  always  gives  up  its  heat  when  Colder 
air  presses  against  its  surface;  Thus  radiation  may 
take  place  at  any  time,  but  it  is  Usually  greater  at  night, 
because  the  air  is  then  colder. 

12.  Light  Waves*- — The  light  waves  which  come  to 
lis  from  the  sun  along  with  the  heat  waves  also  have 
their  part  to  play  in  aiding  the  growth  of  plants  and1 
animals.  Just  what  effect  they  have  we  do  not  certainly 
know,  but  we  do  know  that  light  is  absolutely  necessary 
to  the  growth  of  most  plants.  In  far  northern  coun- 
tries, such  as  Norway  and  Siberia,  farm  crops  make  a 
more  rapid  growth  than  they  do  farther  south.  This 
rapid  growth  must  be  due  to  the  abundance  of  light,  for 
the  days  are  never  very  warm,  and  often  the  ground  is 
frozen  a  few  feet  below  the  surface.  But  during  the 
season  when  plants  grow  the  sun  shines  almost  con- 
tinuously, the  nights  being  only  about  an  hour  long,  and 
the  plants  are  thus  abundantly  supplied  with  sunshine. 

Questions 

1.  What  are  the  three  forms  in  which  all  substances  exist? 
2.  In  which  of  these  forms  does  water  naturally  exist?  3.  When 
water  is  heated,  what  form  does  it  take?  4.  When  water  is 
frozen,  what  form  does  it  take?  5.  How  does  heat  affect  iron? 
6.  How  may  air  be  changed  into  a  liquid ?  7.  What  effect  has 
heat  on  most  substances?  8.  What  effect  has  cold  on  liquids 
and  gases?  9.  What  is  a  thermometer?  10.  How  is  a  ther- 
mometer made?     11.  What  causes  winds?     12.  Tell  how  the 


SUNLIGHT  17 

heat  waves  from  the  sun  set  in  motion  air  currents.  13.  How 
<!<»  winds  cool  the  surface  of  the  earth?  14.  How  are  rains  dis- 
tributed om  the  earth?  15.  How  is  the  earth  kept  warm  at 
night?  16.  \\li;it  i-  HMliatSOBl  17.  Why  do  farm  crops  grow 
more  rapidly  in  northern  than  in  southern  couniries? 


,U'U-i 


18  ELEMENTS  OF  AGRICULTURE 


CHAPTER  III.— Rain 

13.  Work  of  Rain. — We  learned  in  the  last  chapter 
how  rain  clouds  are  formed;  so  now  it  is  in  order  to 
consider  the  work  done  by  the  falling  of  these  clouds  as 
rain.  Besides  supplying  water  for  our  own  use  and  for 
the  needs  of  our  animals  and  crops,  what  does  the  rain 
do  on  a  farm  ? 

14.  Erosion,  Land  Washing. — Did  you  ever  notice 
how  muddy  all  the  creeks  and  rivers  are  after  a  heavy 
rain,  and  did  you  ever  stop  to  think  where  all  this  mud 
comes  from  and  where  it  is  going?  The  gullies  in  the 
hillsides  should  tell  you  where  the  mud  comes  from; 
the  sand  bars  and  islands  in  the  rivers  and  creeks  tell 
you  where  part  of  it  has  gone.  The  next  time  it  rains 
notice  how  the  raindrops  gather  in  low  places  into  little 
streams  of  water,  which  carry  away  particles  of  soil  and 
trash.  As  the  rain  becomes  harder,  more  and  more 
water  gathers  in  these  little  streams,  and  more  particles 
are  moved  along  by  them.  These  small  particles  of  soil 
and  pieces  of  gravel  rushed  along  "by  the  water  grind 
each  other  into  smaller  fragments,  loosen  other  par- 
ticles from  the  soil,  and  so  a  gully  grows  in  the  hillside. 
This  making  of  gullies  is  called  erosion. 

15.  Sediment. — Now,  where  does  the  water  carry  the 
soil  and  trash  which  it  takes  from  the  hillsides  ?  Follow 
one  of  these  little  streams  of  water  and  you  will  see 
that  where  it  reaches  level  ground  it  moves  more  slowly 


RAIN  19 

and  drops  most  of  the  soil  and  trash  which  it  is  carrying. 
But  it  is  still  Buddy  from  the  fine  particles  which  do 
tit-.  These  it  takes  to  the  nearest  creek,  which 
in  turn  takes  them  on  to  BOOM  river,  which  takes  them 
to  a  sea  or  lake,  and  here  they  finalh  settle  to  I  retting 
place  in  fa  1m-,].     The  parti.  1  and  t  rash  carried 

by  the  water  ue  celled  B1  mmi.nt,  and  when  this  settles 
out  from  water  it  is  said  to  he  deposited.     Thus  muddy 
id  to  deposit  sediment. 

Just  try  to  think  of  the  vast  number  of  little  stream- 

of  water  ;it  work  each  day  earning  off  soil  from  exposed 

hillsides.      Much  of  this  -oil   is  deposited  in  the  bottom 

Ksndl  Si  ereekC  and   rivers,  which  are  thus  often  made 

rich  at  the  of  the  hills.     But  most  of  the  snail 

!  which  easily  float  find  their  way  through 

and  rivers  to  a  sea  or  lake,  and  here  they  ;ir«' 

deposited  si  DSTl  of  mud  and  sand.     As  the  river  if 

stantlv  bringing  down  more  mud  and  sand,  these  bars 

grow  and  finally  rise*  from  the  water  to  form  new  land. 

16.  Leaching. — Rain  water  carries  with  it  from  the 

land  other  things  bssidei  mud  and  sand.     Nearh 

one  knows  that  Bet  vatef  M  full  of  salt,  but  few  stop  to 

think  where  this. .-alt   come-   ttOBL      It   OOmefl  from  the 

soil.    Salt  cannot  be  seen  or  tasted  in  ordinary  soil,  but 

ng  with   many  other  substance,  that  are 
also  called  salt-,   becanse   they   an-   like   e..mmon  salt. 

•s  salts  t1 

some  of  which  dissolve  in  water  and  some  do  not    (  <>ni- 

lissolves  very  easily  in  water,  as  do  most  of 

the  other  salts.     When  a  rain  falls,  part  of  the  water 

runs  off  on  the  surface  of  the  soil,  carrying  with  it  mud 


20  ELEMENTS  OF  AGRICULTURE 

and  trash;  but  much  of  the  rain  soaks  down  into  the 
soil  and  comes  out  again  in  springs  and  wells.  The 
rain  water  in  passing  through  the  soil  dissolves  many 
substances  which  it  takes  with  it  when  it  comes  from 
the  soil.  Mineral  springs  result  when  the  water  has 
dissolved  much  of  the  salts  or  other  mineral  matter  in 
the  soil.  A  water  that  has  dissolved  in  it  a  large  quan- 
tity of  certain  minerals  is  a  hard  water.  A  soft 
avater  is  one  almost  free  from  any  dissolved  matte1*. 
When  water  dissolves  substances  and  carries  them  from 
the  soil  it  is  said  to  lea.ch  the  soil.  The  salts  and 
other  substances  which  water  dissolves  in  its  passage 
through  the  soil  are  carried  by  the  water  until  it  reaches 
some  sea  or  lake.  Here  the  salts  remain;  for  when 
water  evaporates  it  carries  nothing  with  it,  the  salts  and 
other  impurities  being  left  behind..  Rain  water,  you 
know,  is  very  pure  and  soft.  So  rivers  are  constantly 
pouring  salts  of  various  kinds  into  the  sea,  and  as  none 
comes  out  again  the  sea  is  becoming  more  salty  every 
day.  This  change,  however,  is  very  slow;  for  seas  and 
oceans,  you  must  remember,  are  very  large  bodies  of 
water,  and  it  takes  a  vast  quantity  of  salt  to  affect  them. 

17.  Rain  as  a  Robber. — Judging  by  the  way  it  be- 
haves to  the  soil,  rain  water  must  be  considered  a  great 
robber,  and  when  farmers  are  careless  and  give  it  a 
good  chance,  it  will  undoubtedly  rob  the  soil  of  much 
that  is  valuable.  If  allowed  it  will  also  cut  great  gullies 
in  exposed  fields,  wash  away  bridges  and  roads,  and 
even  take  away  crops  from  the  fields.  But  where  the 
rain  does  all  this  mischief  it  is  usually  the  fault  of  the 


RAI.V  21 

fanner,  who  has  not  properly  protected  his  fields,  crops, 
tnd  roads. 

18.  Evaporation  as. a  Temperature  Regulator. — An- 
other great  work  done  by  rain  is  to  help  to  keep  the 
earth  from  becoming  too  warm.  The  heat  waves  from 
t Im-  miii  evaporate  from  the  earth's  surface  gnat  quan- 
of  water  to  form  clouds.  The  moisture  which 
forms  these  clouds  has  been  warmed  by  the  heat  waves, 
ami,  when  it  rites,  carries  with  it  much  heat  from  the 
earth.  Rising  shore  the  earth,  the  clouds  come  in  con- 
tact with  the  colder  upper  air;  here  their  heat  is  given 
up.  or  radiated,  and  thev  fall  back  as  rain.  The  h.at 
which  thev  radiate  peases  through  the  thin  upper  air 

and  is  lust  in  outer  ftp* 

/  \/7  7.7i//  \  rs 

/.    '/<//..   I  ftafi  tinnhhr  iiraili/  full  of  tinier  anil  in  it  stir  up 
I  M  'r.v  ifou  stoi>  stirring  notirr  fcON  the 

•voi/  porta  Us  hri/in    tn  s<tth%  ,in, I  bSMTM   wikiok   ffffoll 

"om  first,    \otue  also  thitt  MM  fine  particbs  contiuu.    to 
float  in  tin-  miii  r  jur  hours  or  even  days.     Tht$4  <o«  rim/  parti- 
■■<    <i<  t<  r  n  long  time  from  still  hnt>  r.     \ihl  a  lit- 
th   tiluni  solution  to  this  rloinhf  uut'r  and  see  \rhat  tcill  happen. 
.'.    /  >nporate  rlnir  spring    »/"  /<  <m   ilish,   and  notice 

th,    ih  posit  left  in  tin   ,hsh.      I  Ins  ill  p.  ./♦•  tip  of  the  salt  § 

trhich  the  spring  trater  contains  and  tchich  it  has  dissolved  from 
the  soil.  Rain  trater  if  evaporated  in  a  clean  dish  leaves  almost 
no  deposit. 

Questions 

1.  How  are  rain  clouds  formed?  2.  With  what  does  the  rain 
supply  uh?  1  How  do  rains  affect  exposed  lards!  4.  How  is 
a  stilly  formed!  5.  Where  does  the  soil  go  which  is  washed 
fioin  iulUi.i.s  bv  the  rains!    6.  Why  is  the  soil  of  creek  and 


22  ELEMENTS  OE  AGRICULTURE 

river  bottoms  usually  richer  than  the  soil  of  hillsides  ?  7.  When 
you  stir  up  soil  in  water,  which  particles  settle  first  after  you 
stop  stirring?  8.  Why  does  not  the  water  become  perfectly 
clear  at  once?  9.  Where  does  the  sea  get  its  salt?  10.  How 
are  salts  carried  from  the  land  to  the  sea?  11.  Does  rain  water 
contain  any  salt?  12.  What  is  a  hard  water?  13.  What  is  a 
soft  water? 

PROBLEM 

An  acre  of  soil  one  foot  deep  contains  43,560  cubic  feet.  The 
Mississippi  River  carries  annually  to  the  ocean  about  3,702,- 
758,400  cubic  feet  of  solid  material.  How  many  acres  of  soil 
one  foot  deep  would  this  amount  of  material  form  ? 


ATMOSPHERE  23 


CHAPTER  IV.— The  Atmosphere 

19.  Extent  of  the  Atmosphere. — The  earth  is  com- 
pletely rarrotmded  by  I  mixture  of  several  gases,  which 
is  called  the  ATM08PHXS1,  or  .\m.  The  quantity  of  air 
becomes  less  and  less  as  the  distance  from  the  earth's 
surface  increases,  until  finally  there  is  no  more  air,  and 
what  is  called!  outer  space  begins.  No  one  knows  just 
how  far  the  itmosphere  extends  above  the  earth,  but  it 
is  variously  estimated  at  from  200  to  500  miles.  Per- 
sons climbing  high  mountains  all  notice  how  the  <pian- 
air  diminishes  as  they  ascend)  and  how  the  cold 
i-es.  In  the  thin  air  of  high  mountain  tops 
breathing  becomes  difficult,  and  finally,  owing  to  a  lack 
of  air  and  to  the  int.  use  cold,  a  point  is  reached  I- 
which  man  cannot  climb,  It  i-  probable  that  more  than 
90  per  fid  of  the  atmosphere  is  included  in  the  first 
fifteen  miles  above  the  earth. 

While  the  thin  up|>or  air  will  not  furnish  breath  for 
man  0  <  vrs  the  useful  purpose  of  proti 

irth    from   th«>   rasi    number  of  meteOTS — shooting 
M   they  are  called — which  arc  constantly    falling 
The  nambef  of  meteors  striking  the  upper  air 
in   twenty-four  hours  has  been  cettmstfld  at  two  mil- 
lion.     Meteors  travel  with  enormous  speed,  and   when 
itrQce  the   upp.r  air  the  friction   produced  is  so 
great  that  it  causes  enough  heat  to  burn  them  up.    Most 
meteors  are  small  bodies,  and  are  burned  up  so  far 


24  ELEMENTS  OF  AGRICULTURE 

above  the  earth  that  the  little  light  they  give  off  is  not 
visible.    Few  meteors  ever  reach  the  earth. 

20.  Composition  of  the  Air. — Chemists  tell  us  that 
air  is  a  mixture,  consisting  principally  of  two  gases, 
nitrogen  and  oxygen,  but  containing  in  addition  to 
these  two  main  elements  small  quantities  of  several 
other  gases,  and  even  some  liquids  and  solids.  A  gas 
called  carbonic  acid,  or,  more  properly,  carbon  dioxide, 
another  gas,  ammonia,  and  water  vapor  are  three  im- 
portant gases  found  in  small  quantities  in  the  air. 
Water  in  the  rain  clouds  and  mist  make  up  the  liquid 
portion  of  the  air,  and  dust  particles  and  bacteria  make 
up  the  solid  portions.  Now,  what  are  these  various 
substances — nitrogen,  oxygen,  ammonia,  etc.?  They 
are  what  chemists  call  elements  and  compounds. 

21.  Elements. — Nitrogen  and  oxygen  are  elements. 
They  are  called  elements  because  they  cannot  be 
divided  into  anything  else.  Iron  is  an  element;  it  may 
be  divided  into  the  finest  possible  pieces,  but  it  is  still 
iron.  There  is  no  known  way  of  dividing  iron  into  any- 
thing but  iron,  and  this  is  true  of  nitrogen  and  oxygen. 
All  substances  that  cannot  be  divided  into  anything 
else  are  called  elements.  There  are  something  over  70 
elements  known,  but  we  shall  be  concerned  in  this  book 
with  not  more  than  16  or  17  of  them. 

22.  Compounds. — Two  or  more  elements  may  unite 
with  each  other  to  form  substances  entirely  different  in 
appearance  or  behavior  from  either  of  the  two  elements 
themselves.  Substances  made  up  of  two  or  more  ele- 
ments are  called  compounds.  Water  is  a  compound, 
for  it  can  be  divided  into  two  gases,  oxygen  and  hydro- 


ATMOSPFJERE  25 

gen,  neither  of  which  resembles  water.    All  compounds 
can  be  divided  into  two  or  more  elements. 

23.  Mixtures. — Two  <>r  more  elements,  or  compounds, 
may  be  mixed  and  still  retain  all  their  individual  prop- 
erties. When  this  takes  place  the  result  is  a  mixture. 
Salt  is  mixed  with  flour  to  make  bread,  and  in  the  mix- 
tun-  we  cannot  see  any  salt,  but  we  can  taste  it  and 
know  from  its  taste  that  the  salt  is  unchanged. 

.  air  is  a  mixture  of  several  elements  and  com- 
pound us  see  what  these  various  substances  are 
that  go  to  make  up  air. 

24.  Oxygen. — This  element  is  a  gas,  and  makes  up 
nearly  23  per  cent  by  weight  of  the  air.  It  is  the  most 
abundant  substance  on  earth,  making  up  eight-ninths 
of  the  weight  of  water  and  about  50  per  cent  of  the 
weight  of  Band.  About  one-third  of  the  weight  of 
and  r«  adfl  09  of  ow^en.  and  all  plant-  and  ani- 
mals contain  large  quantities  of  the  gas.  Oxygen  ifl  I 
very  active  gaa,  «lv  to  combine  with  other 
rabetaneea,  which,  when  the  union  takes  plane,  an 

come  oxranm     When  rabatanoei  combine  with 

tlOO   prod  Thus  the  carbon    in 

coal  when  it  hums  onitea  with  oxygen  to  form  a  gas 
called  carbon  dioxide,  and  gifee  <>fT  much  heat  * 
bined  with  another  gas  called  hydrogen^  oxygen  forms 
a  liquid  which  we  know  as  water.  Combined  with  iron, 
it  forms  a  solid  called  iron  ore.  In  plants  and  animals 
it  occurs  in  combination  as  water,  and  also  combined 
with  some  other  substances  to  form  solids.  We  breathe 
oxygen  in  the  air,  we  drink  oxygen  in  water,  and  we  eat 


26  ELEMENTS  OF  AGRICULTURE 

oxygen  in  our  food.     We  could  not  live  for  a  moment 
without  it. 

Oxygen  alone  is  too  active  to  support  properly  the 
growth  of  plants  and  animals.  In  the  air  it  is  mixed 
with  a  slow,  inactive  sort  of  gas  called  nitrogen. 

25.  Nitrogen. — In  its  habits  this  element  is  very 
much  the  reverse  of  oxygen.    It  makes  up  nearly  four- 

'  fifths  of  the  volume  of  the  air,  or  77  per  cent  by  weight, 
but  does  not  readily  combine  with  other  substances.  It 
is,  however,  very  useful  in  agriculture,  as  no  plant  or 
animal  can  grow  without  a  supply  of  nitrogen.  But  a 
few  plants  have  the  power  of  obtaining  nitrogen  from 
the  air,  and  animals  obtain  their  nitrogen  only  from 
plants.  Small  quantities  of  oxygen  and  nitrogen  are 
found  in  the  air,  combined  with  two  other  elements 
called  hydrogen  and  carbon. 

26.  Hydrogen. — This  element  is  a  gas,  and  is  the 
lightest  of  all  known  substances.  All  of  the  hydrogen 
found  in  the  air  is  combined  with  other  elements.  Com- 
bined with  oxygen  it  forms  water;  combined  with 
nitrogen  it  forms  ammonia. 

27.  Carbon. — This  element  is  a  solid  substance,  and 
is  well  known  in  the  shape  of  mineral  coal,  which  is 
nearly  all  carbon.  The  diamond  is  also  very  nearly  pure 
carbon,  and  so  is  the  lead  of  an  ordinary  lead  pencil. 
Carbon  when  heated  in  excess  of  air  unites  very  readily 
with  oxygen,  forming  the  compound,  carbon  dioxide. 
Thus  when  coal  is  burned  most  of  it  disappears  into 
the  atmosphere  as  a  gas,  carbon  dioxide,  leaving  behind 
only  a  few  ashes.  A  large  part  of  all  plant  and  animal 
bodies  is  made  up  of  carbon. 


ATM08t»HEttfi  27 


Questions 

1.  About  how  far  nl><.\.-  the  .arth  i-  tin-  atmosphere  pditvtd 
to  extern  1°:    i.  fflffliiro  li  flit  »\r  ilfimwtT    .'{.  n«>w  doe*  th*  thin 

i'|.|mt  an  j.ftr.-t  tlir  .arth  .'  1.  What  i-  an  «-h  ni.nt  .  ."..  \\  hat 
in  a  compound?  0.  What  is  a  Mixture  1  7.  U  air  an  element, 
Mtepoaad  <>r  nlxtarel  B.  Nam.-  row  gMee  found  in  t !»<■  atam 
ph.Ti-.     !».  Describe  oxygUL     10.  Describe  nitrogen.     II.  Dt* 

»<  nU-  KjdrogOL      I-     Name  three  Will  kimu n   t<»rius  o|  .-arl...ii. 

PROBLBM 
h  acre  of  load  are  about  16,200  i<»n*  ot  air.    it 

tail   amount    Of  air  OOBtOJnf   29    |'<  r   cent    l.v    freight    <>t    a 
liml  the  Wright  ..i  Oxygen  gU  renting  <>n  .;..  h  acre. 


28  ELEMENTS  OF  AGRICULTURE 


CHAPTER  V.— The  Atmosphere 
(  Continued  ) 

£8.  Carbon  Dioxide. — Though  this  gas  makes  up  a 
relatively  small  proportion  of  the  atmosphere,  it  is  very 
important,  as  it  supplies  a  large  part  of  the  food  of  all 
growing  plants.  The  air  about  cities  usually  contains 
more  of  this  gas  than  the  air  of  the  country.  The  many 
fires  which  are  constantly  kept  going  in  cities  give  off 
great  quantities  of  this  gas.  Ordinary  air  contains  about 
.035  per  cent  by  volume,  or  about  0.06  per  cent  by 
weight  of  carbon  dioxide.  This  seems  a  very  small 
amount,  but  when  multiplied  by  the  vast  oceans  of  air 
it  becomes  a  large  sum.  It  is  estimated  that  the  air 
covering  every  acre  of  ground  contains  about  28  tons 
of  carbon  dioxide,  which  give  lO1/^  tons  of  pure  carbon. 
The  supply  of  carbon  dioxide  in  the  air  remains  always 
about-  the  same.  The  amount  taken  up  by  plants 
during  their  season  of  growth  is  replaced  by  the  gas 
from  fires,  the  breath  of  man  and  beast,  and  other 
sources.  t 

29.  Ammonia. — This  compound,  often  called  harts- 
horn, is  made  up  of  nitrogen  and  hydrogen.  It  has  a 
very  powerful  odor,  but  the  air  contains  so  little  of  it 
that  it  is  not  perceptible.  This  gas  is  very  easily  dis- 
solved in  water,  and  rain  washes  it  from  the  air  and 
carries  it  to  the  soil,  where  it  may  become  plant  food. 


ATMOSPHERE  29 

Though  the  amount  in  the  air  is  very  small,  it  is  of 
MUM  importance  to  plants. 

30.  Moisture. — Water  is  found  in  the  air  as  a  gas 
known  as  \\  a  i  i  i;  VAPOR.  The  amount  of  water  vapor 
in  the  air  is  very  variable,  but  warm  air  contains  more 
than  cold  air.  In  cold  air  the  water  vapor  condenses  to 
form  clouds  <>r  mist,  in  which  form  it  is  no  longer  a  gas, 
but  a  liquid.    Notice  how  dropi  of  water  collect  on  the 

Outside  of  a  gl*8t  of  icc-cohl  water;  the  warm  air  which 
(nn tain-  wafc  r  vapor  comes  in  contact  with  the  cold  sur- 
face of  the  glass,  is  cooled  down,  and  the  water  vapor 

uses  to  form  drops  of  water.    This  is  a  good  ex- 
ample of  how  dew  is  formed.     At  night  when  no  h.  at 
from  the  sun  the  air  Incomes  quite  cool — cooler 
than   the  earth,   which   is   warmed   by   the  heat  it  has 

1  up  during  the  day.     Now,  when  the  air  be 
cool  enough,  the  water  vapor  it  contains  condenses  to 
form  drops  of  water,  which  ore  gently  deposited  on  the 
surface  of  the  earth  and  fonn  dew.    I),  w  is  rain,  formed 

the  earth's  surfa<  i  the  air  becomes  suffi- 

ciently eold,  the  dew  fre<  ni  and  forms  frost. 

Moisture  in  the  air  perves  a  useful  purpose  in  helping 
to  keep  the  earth  warm.      The  heat  waves  which  come 

from  the  sun  move  with  wonderful  rapidity,  about 
>0  miles  in  a  second  of  time,  and  pass  through  the 
atmosphere  as  easily  as  water  through  a  sieve.    Striking 
the  earth's  surface,  these  heat  wav<«s   warm    it    up:   in 
Other  -tart  up  other  hen-  UDOng  the 

surface   ii  of  the  earth.     The  h-  -   thus 

!   in  the  earth's  surface  move  nuni.  more  slowly 
than  the  heat  waves  from  the  sun,  and  they  in  time 


30  ELEMENTS  OF  AGRICULTURE 

start  up  other  slow-moving  heat"  waves  in  the  air  press- 
ing against  the  earth's  surface.  The  heat  waves  started 
in  the  air  tend  to  rise,  but  the  moist,  dense  air  near  the 
earth's  surface  checks  their  upward  progress  and  holds 
them  till  the  air  becomes  thoroughly  warmed  by  their 
motion.  Eising  slowly  through  the  dense  air  near  the 
earth,  the  "heat  waves  finally  reach  the  thin  upper  air 
through  which  they  pass  very  easily,  and  are  soon  lost 
in  outer  space.  High  mountain  tops  are  surrounded 
by  thin  air,  through  which  the  heat  waves  from  the 
earth  pass  so  rapidly  that  it  never  becomes  thoroughly 
warm,  consequently  they  are  always  cold.  The  dense 
layer  of  air  near  the  earth's  surface  acts  like  a  heavy 
blanket  or- covering;  the  thin  air  of  mountain  tops  is  a 
very  poor  covering. 

Dew  and  frost  seldom  occur  on  cloudy  nights,  because 
the  moisture  in  the  clouds  holds  the  heat  waves  from 
the  earth,  which  keep  the  air  warm  and  prevent  the 
condensation  of  water  vapor.  Dust  and  smoke  have 
much  the  same  effect  as  clouds,  and  for  this  reason 
smoke  is  sometimes  used  to  prevent  frost.  Wind  also 
prevents  frost,  the  air  being  kept  in  such  rapid  motion 
that  little  or  no  moisture  is  deposited.  Moisture,  dust, 
and  smoke  all  tend  to  prevent  radiation.  In  dry  air 
radiation  takes  place  rapidly,  and  consequently  desert 
countries  are  nearly  always  cold  at  night,  though  warm 
in  the  day.     • 

31.  Solid  Substances  in  Air. — Dust  particles  may 
often  be  seen  in  the  air,  and  especially  is  this  true  in 
dry  weather,  when  they  become  so  numerous  as  to  be 
very  disagreeable.    Eain  washes  most  of  the  dust  from 


ATMOSPHERE  .  31 

the  atmosphere,  leaving  the  air  fresh,  clear,  and  cool. 
Along  with  the  dust  particles,  and  often  carried  by 
thrm,  a iv  many  -mall  bodies  called  bacteria.  They 
arc  living  bodies,  but  such  small  ones  that  they  can  be 
Been  only  by  means  of  a  good  microscope.  Some  bac- 
teria cante  disease  in  plant-  and  animals,  but  others  are 
\t  r\  beneficial  t<»  both,  as  you  will  learn  later  on.  No- 
tfae  mold  which  forms  on  starch  paste  when  it  is 
hft  op.  11  to  the  air.  This  mold  is  caused  by  bacteria, 
which  feed  on  the  paste,    if  some  substance  poisonous 

to  bacteria  he  mixed  with  paste  no  mold  will  form,  and 
keeps  till  it  dries  up.     Oil  of  win!. 

nous  to  certain  bacteria,  and  i<  much  used  for  pre- 
serving  starch  paste. 

32.  Meteorology. — Wind,  rain,  and  sunshine  do  not 
come  and  <:<>  by  chance;  their  movements  are  regulated 
by  lav  act   as   tl,  Iging  day  to  night  and 

night  back  to  day  again.  '  By  studying  these  laws  we 
may  lean  when  to  expect  a  change  of  weather.  Scat- 
tered over  our  country  are  many  weather  bureaus,  where 
men  employed  by  the  government  are  constantly  watch- 
ing and  recording  the  changes  and  movements  of  sun- 
shine, wind  and  rain,  which  changes  go  to  make  Dp 
what  we  call  w i:\tiiku.  It  is  very  true  that  man  cannot 
control  the  coming  and  going  of  sunshine,  wind,  and 
rain,  hut   |  -sful   fanner  knows  how  to  regulate 

h\<  farming  to  suit  the  weather,  and  is  always  prepared 
to  meet  the  changi-s  which  are  constantly  occurring. 
Some  knowledge  of  meteobolooy— the  science  of  the 
weather — is  necessary  in  successful  farming.  This 
knowledge  usually  comes  from  years  of  experience  and 


32  ELEMENTS  OF  AGRICULTURE 

observation  on  the  part  of  the  farmer,  but  now  the 
weather  bureaus  supply,  for  the  asking,  information 
which  has  been  collected  as  the  result  of  years  of 
patient  labor.  Each  farmer  should,  however,  keep  a 
record  for  his  own  farm  or  locality,  and  if  the  work  be 
done  carefully  and  systematically,  it  will  prove  of  value 
not  only  to  him,  but  to  his  community  and  to  his  chil- 
dren after  him. 

Questions 

1.  Why  is  carbon  dioxide  important  to  growing  plants? 
2.  Why  is  there  usually  more  carbon  dioxide,  in  the  air  of 
cities  than  in  the  air  of  the  country?  3.  What  is  ammonia? 
4.  What  is  water  vapor?  5.  Which  contains  the  more  water 
vapor,  warm  or  cold  air?  6.  When  the  water  vapor  in  the  air 
condenses  on  the  surface  of  the  earth,  what  is  it  called?  7.  How 
is  frost  formed?  8.  How  does  dense,  moist  air  behave  towards 
the  heat  waves  from  the  earth?  9.  Why  are  the  tops  of  high 
mountains  colder  than  the  country  below?  10.  What  do  the 
dust  particles  in  the  air  often  carry  with  them?  11.  What  is 
meteorology  ? 


PLANTS  AND  TITEIIt  SEED  33 


PART  II.-Plaj*ts 


CHAPTEB  V  l.     Plasm  and  Their  Seed 

33.  Annuals,  Biennials,  and  Perennials. — Most  of  the 
plants  cultivated  <>n  the  farm  arc  grown  from  seed',  a 

row  from  cuttings,  an«l  a  few  from  roots,  but  the 
more  important  farm  crops  all  grow  from  seed.  Plants 
are  often  divided  into  three  groups — annuals,  biennials, 
and  perennials.  These  words  refer  to  the  length  of  the 
plant's  lit"..     A  \  \  ials  are  plants  living  about  one  year; 

iais,  plants  living  about  two  years;  and  n:i:i  \ 
\i  us,  plants  which  live  on  year  after  year  for  an  in- 
definite period.  Annuals  grow  rapidly  to  their  full 
a  crop  of  seed,  and  die  all  in  about  one 
year's  time  Bi<  nnials  often  reach  their  full  size  in  one 
year,  but  do  not  produce  seed  till  the  second  year.  After 
producing  a  crop  of  seed  they  also  die.  These  two 
classes  of  plants  produce  only  one  crop  of  seed.  Peren- 
nials have  no  fixed  lifetime — some  such  as  oak  trees  live 
to  be  hundreds  of  years  old,  others  live  only  a  few 
years.  Most  perennials  produce  seed  each  year;  others 
only  at  longer  intervals. 

34.  Seed. — Most  farm  crops  grow  from  seed;  corn, 
oats,  wheat,  cotton,  rice,  and  tobacco  all  come  from 
the  planting  of  seed.  Each  crop  produces  but  one  kind 
of  seed,  and  this  seed  when  planted  in  turn  produces 

3 


34  ELEMENTS  OF  AGRICULTURE 

again  the  crop.     There  is  never  a  mistake — corn  comes 
from  corn  seed  and  wheat  from  wheat  seed  with  abso-< 
lute  certainty. 

A  seed  is  the  egg  from  which  a  plant  is  hatched.  An 
ordinary  seed  may  well  be  compared  to  an  egg.  It  con- 
sists usually  of  an  outer  shell  protecting  the  soft  inner 
portion,  which  is  really  the  young  plant  folded  up.  A 
sitting  hen  warms  her  eggs  with  the  heat  of  her  body 
till  the  necessary  changes  have  taken  place  in  the  egg, 
then  the  chick  begins  to  stir,  and  soon  bursting  the  shell 
comes  into  the  world  a  living  animal.  The  apparently 
lifeless  egg,  when  warmed  by  the  hen,  is  changed  into 
a  living  chicken.  The  equally  dead-looking  seed,  when 
warmed  in  the  soil  by  the  sun's  heat  waves,  bursts  its 
shell  and  becomes  a  living  plant.  Most  plants  drop 
their  seeds  late  in  the  fall,  when  a  comparatively  small 
number  of  heat  waves  come  to  the  earth  from  the  sun, 
and  the  earth  is  in  consequence  cool.  The  seed  lies  on 
the  surface  of  the  ground  all  winter,  the  soft  little  plant 
folded  up  within  being  protected  from  the  cold  and  wet 
by  the  hard  outer  shell.  In  the  spring,  when  the  heat 
waves  begin  to  strike  with  more  and  more  force  on  the 
earth's  surface,  the  plant  folded  up  in  the  seed  begins 
to  feel  their  effect,  and  soon  bursts  its  shell  and  begins 
its  life  as  a  young  plant.  The  warmth  of  the  hen's 
body  seems  all  that  is  necessary  to  hatch  the  egg,  but 
other  things  besides  heat  are  necessary  to  hatch  out  a 
seed.  Seeds  may  be  kept  in  a  warm,  dry  place  for  years, 
and  yet  never  sprout ;  but  so  soon  as  they  are  moistened 
they  will,  if  alive,  begin  to  sprout  and  grow.  Water, 
then,  as  well  as  heat,  is  necessary  for  the  sprouting  of 


II   \N  I       \M)  THEIR  SEED  35 

seeds.     \  wed  plant  d  deep  in  the  soil  will  not  grow,  no 
r  if  supplied  with  water  end  beat;  but  on  or  neai 
ufacc  it  sprouts.    Air,  then,  must  also.be  i 
sary  fur  the  sprouting  of  seed  means  of  i  f<iw  sim- 

ple experhnenl  bed  at  the  end  of  this  chapter, 

anv  one  may  prove  for  hi-  nun  -  £  C 

faction  thai  water,  heat,  and  air  are. 

necessan   to  sproutii 

\     seed     contain^     not     only     the 

young  plant  or  embryo,  but  a 
sufficient,  store  of    food  to  nourish 

it  until  it  can  take  its  food  from 
the  soil.  Take  i  fresh  been  and 
notice  how  it  is  divided  into  two 
equal  pari  '  at  one  end  by  a 

small   stem.    These   two    parts   arc 

called  the  EOEKD  u:\vi.-.  and  eon- 
tain  of  food  sufficient  to 
nourish  the  growing  plant  until  it 
can  feed  itself  through  its 
i  1  shows  a  young  bean  plant  re- 
cently sprouted;  c  e  are  the 

.  and  as  the  plant  grows  ! 

they  grow  -mailer  till  they  are  anally-  ( 

up  and  only  a  wilted  shell  ^JS^JS^ttoViiS 

.    Which    1000     fall-    olT    from  ,  ^^j! 

the  stem  ,i,ph-) 

All  seeds  an>  provided  with  a  store  of  food  for  the 

use  of  the  young  plant,  for  young  plants,  like  young 

enima  <>t  able  to  take  care  of  themselves  just  at 

feat 


36 


ELEMENTS  OF  AGRICULTURE 


The  nourishment  for  the  young  plant  is  not  always 
-tored  in  the  seed  leaves  as  it  is  in  the  bean, -but  often 
surrounds  the  young  plant,  as  in  the  corn  seed,  as  shown 
in  Fig.  2. 


Fig.  2. — Grain  of  corn  showing  stages  of  germination  :  A,  section  of 
ripe  seed  enlarged ;  /,  seed-food,  the  portion  that  nourishes  the  young 
plant:  g.  germ  of  seed.  B,  showing  seed  just  sprouted;  C,  showing 
sprouting  further  advanced.  /»,  showing  sprouting  still  further  ad- 
vanced; young  plant  just  showing  a  hove  ground.  (Original  drawing 
from  photographs.) 


i:\ri:h>iUENT 


Fill  an  ordinary  deep  plate  with  sand  or  common  soil,  ami 
moisten  it  thoroughly  with  water.  Then  cut  a  piece  of  flannel 
cloth  just  large  enough  to  fit  in  the  plate,  and  moisten  thor- 
oughly. Cover  the  soil  icith  the  damp  flannel  cloth,  and  over  it 
scatter  the  seeds  to  be  tested.  Cover  with  another  piece  of  damp 
cloth.  Finally  cover  the  whole  with  another  plate,  and  set  away 
in  a  warm  place,  where  the  temperature  is  about  80°.  Fig.  3 
shows  a  cut  of  this  arrangement.  Keep  the  flannel  and  soil 
damp  but  not  wet;  if  too  much  water  is  added,  the  seeds  will 
rot.    If  the  cloths  are  kept  dry,  the  seeds  will  not  sprout  at  aW, 


37 


>,, ut   if  //  i (urc  is  kept  below  ^0°  or 

in:  .     If  MM  "/'  thrse  tutme  seeds  be  planted  deep  below 

the  surface  of  the  soil,  a  foot  or  more,  they  will  never  come  up, 


I  i'..         >impl.ap|» .<■  ■  rm in;. 1 1 lie  need: 

.  1886,  page  181.) 


i ;  /{,  open 


but  on  the  surface  they  sprout  readily,    I'rom  experiments  such 
as  this  that  seeds  must  be  supplied  with  certain  quan- 

iter,  and  air  before  they  can  sprout. 


Questions 

1.  What  is  an  annual?    2.  What  is  a  biennial?    3.  What  is  a 

perennial?     4.  How  ninny  crops  of  seed  does  a  biennial  plant 

ptotaetl     .">.   ]\<,w    uft.u    .!<»    most    j..r.!ini;ils    produce    seed? 

I  i^  a  h.-ii\  sjg  <  hanged  to  a  chicken?    7.  How  does  beat 

moat  seeds?    8.  \\  hat  in  necessary  besides  heat  to  sprout 

seeds? 

PROBLEM 

\!.ik.-  |  li-t  ..f  all  U  "H  kii..A   hi  y.uii  neighborhood, 

and  divide  them  iuto  annuals,  biennial!  and  perennials. 


38  Elements  of  agriculture 


CHAPTER  Vli.— Parts  of  a  Plant 

35.  Organs  of  Reproduction.—- Many  plants,  as  you 
know,  produce  flowers^  fruit,  and  seed;  but  these  parts/ 
or  organs,  as  they  are  called)  have  nothing  to  do  with 
feeding  the  plants  which  produce  them.  From  the 
flowers  come  the  fruit  and  seeds;  the  seeds  produce 
other  plants  like  the  ones  producing  them;  hence,  the 
flower,  fruit,  and  seed  are  called  the  organs  of  repro- 
duction, because  they  reproduce  other  plants. 

36.  Organs  of  Vegetation. — Most  plants  which  grow 
on  the  farm  have  three  distinct  parts,  two  of  which,  the 
stem  and  leaves,  are  above  ground  and  may  be  readily 
seen.  The  third  part  of  the  plant — its  roots — is  buried 
beneath  the  surface  of  the  soil,  and  can  only  be  seen 
by  digging  down  in  the  earth  or  by  pulling  the  plant 
up.  These  three  parts,  or  organs,  are  necessary  to  the 
health  and  growth  of  a  plant.  Cut  off  a  plant's  roots 
and  it  soon  withers  and  dies.  Cut  off  all  its  leaves  and 
its  growth  is  checked,  and  often  the  plant  is  killed.  Cut 
away  the  stem  and  the  leaves  soon  die;  the  roots,  how- 
ever, if  left  in  the  ground,  may  put  forth  a  new  stem. 
Each  of  these  three  organs  has  its  work  to  do  in  feed- 
ing the  growing  plant.      They  are  called  organs  of 

VEGETATION. 

When  the  young  plant  bursts  its  shell  and  begins  to 
grow,  one  part,  the  root,  grows  down  into  the  earth ;  the 
other,  the  stem,  grows  in  the  opposite  direction,  towards 
the  light.    Fig.  2,  page  36,  shows  how  a  grain  of  corn 


PARTS  OP  A  PLANT  39 

sprouts.  Tli.'  plant  never  makes  a  mistake  in  starting 
to  grow;  the  roots  always  go  into  the  soil  and  the  tfc  m 
nntl  lean  |  to  the  light  and  air  above.  Why  they  do  this 
i  not  know,  hut  we  do  know  that  the  roots  keep  OH 
growing  into  the  soil,  spreading  out  in  search  of  food 
;m<l  water  and  taking  a  firm  hold  to 
rapport  the  stem  and  leaves  above.  At 
first,    as   yon    have    been    told,    the    food 

1  op  in  the  seed  feeds  the  young 
plant.  Later  on,  when  the  plant  be- 
coin.  dfl  itself  through 

♦  he  roots  and  |<  av< 

37.    Roots. — We    nil     recognize    the 
great    variety    of    h-.\  [need    hv 

different  kinds  of  plants,  hut  the  roots 
buried    beneath    the    ground    are  ' 
familiar,  and  while  not  nearly  so  varied 

in  appearance  as  the  leares,  an  of  many 
kinds  and  shapes.  Many  plants  are  pro- 
vided with  one  large  main  root,  which 
goes  deep  into  the  soil.  This  root  is 
called  the  TAPROOT,  and  its  bran<  Ins 
an-  railed  i.ati  i;\i.  i:<«n  s.  |  ■-.  1  shows 
R?Ldphoio"  U»  taproot  pf  |  salsify  plant.  When 
the  taproot  is  enlarged,  as  in  the  salsify 
and  turnip,  it  is  called  a  FLESHY  ROOT. 

[nstead  of  our  main  root,  many  plants  have  a  number 
of  roots  of  equal  -ize.     Pig,  :>  -hows  the  roots  of  I 
plant.     Such  roots  are  known  as  GLU8TF.1  i:own 

ROOTS.     When  thev  an   enlarged,  as  in  the  sweet  |K>tato, 
Fig.  6,  they  are  called  tuberous.      Lateral,  or  side 


40 


ELEMENTS  OF  AGRICULTURE 


roots,  and  the  younger  portions  of  main  roots  are  cov- 
ered with  fine  thread-like  branches  that  are  called  root 
hairs.  The  little  roots  are  so  small  and  delicate  that 
they  are  difficult  to  find.  But  they  may  be  seen  by 
sprouting  radish  seed  as   described  in   experiment  on 


Fig.  5.—  Roots  of  a  young 
corn  plant;  clustered  or 
crown  roots.  (Original 
drawing  from  photograph.) 


Fig.  6.— Tuberous  root.s  of  the  sweet 
potato.  (Original  drawing  from  photo- 
graph.) 


page  36.  Fig.  7  A  shows  a  young  radish  plant  sprouted 
in  this  way ;  the  root  hairs  show  like  fine  threads.  Fig. 
7B  shows  a  young  radish  plant  pulled  from  the  soil; 
Here  the  root  hairs  are  covered  by  particles  of  soil,  and 
if  they  are  washed  off  the  root  hairs  are  destroyed.  The 
root  hairs  are  delicate  tubes  through  which  the  plant 
draws  much  of  its  food  and  water.     Fig.  8  shows  the 


PARTS  OF   A   PLANT 


41 


root  haire  of  an  oat  plant  highly  magnified.  Water 
easily  passes  through  the  walls  of  the  root  hairs,  and 
from  them  passes  on  into  the  main  roots,  and  finally 
into  the  plant  stem.  Each  root  hair 
is  like  a  miniature  well,  through 
which  water  rises  into  the  main 
roots  of  the  plant.  When  a  grow- 
ing   plant    is    taken    from    the    soil 


7.— You  ng    r  a  <l  I  »  li 
plant  :  .4.  younjf  plant  tproai* 

in-  iii.   p.  H;  /?.  j  oan| 

pullet 

mil   .i •  in    |.  it  <>i ... 


.1    plant    in 

bow« 

v.. i  I    parlli  I-- 
be  I  n  R  dim 

Df  t  h  ••  ro 
(Kniiii  HiwIirpN  : 

I'llN  >.  d,    I'll. I/.   II. 


and   replanted   it   mark   always  wilts,  taking  i 
days  to  revive.     It  wilts  because  many  of  its  root  hairs 
are  destroyed,  and  consequently  p  supply  is  les- 

tn  tune  new  root  hair-  are  formed  and  the  plant 
Roots  are  useful  to  plants  in  two  ways:  First,  they 


42  ELEMENTS  OF  AGRICULTURE 

supply  the  portion  of  the  plant  growing  above  the 
ground  with  a  firm  support.  Second,  they  supply  the 
plant  with  much  of  its  food  and  water. 

The  root  hairs  and  smaller  roots  supply  most  of  the 
food  and  water.  The  larger  and  stronger  roots  serve 
as  carriers  of  food  and  support  the  growing  plant. 

38.  Stems. — Stems  are  more  varied  in  appearance 
than  roots.  In  large  plants,  such  as  trees  and  shrubs, 
the  stem  consists  of  a  main  upright  portion  called  the 
trunk,  which  is  provided  with  a  number  of  branches 
called  limbs,  and  they  in  turn  are  provided  with 
brandies  called  twigs..  In  most  plants  the  stems  are 
upright,  and  the  general  direction  of  the  limbs  is  the 
same.  But  there  are  many  plants  provided  with  hori- 
zontal stems  growing  along  the  surface  of  the  soil ;  other 
plants  are  provided  with  drooping  stems,  which,  after 
reaching  a  certain  height,  turn  towards  the  earth  again. 
Still  others  are  provided  with  twining  stems,  and  can 
only  grow  upward  when  provided  with  a  support  around 
which  they  grow.  But  whatever  the  shape  and  size  of 
stems  they  all  serve  the  same  purpose.  They  bear  the 
leaves,  flowers,  fruit,  and  seed  of  the  plant,  and  they 
serve  to  distribute  the  food  and  water  taken  in  by  the 
roots  and  leaves. 

39.  Leaves. — Leaves  are  more  varied  in  size  and 
shape  than  either  the  stems  or  roots,  but  most  leaves 
have  one  striking  point  in  common — namely,  their  color. 
With  a  few  exceptions  all  living  leaves  are  green,  and 
a  loss  of  this  color  only  occurs  through  disease  or  death. 
The  stems  of  young  plants  and  the  tender  twigs  of 
older  plants  are  often  as  green  as  the  leaves.    The  veins 


>0P  A  PLANT 


43 


of  leave!  an  r  ■  •ntinuation  of  the  stem,    l 

■howi  reins  in  a  leaf  of  beetle-wi 
The  green  color  of  Leavei  u  doe  to  the  presence  of  a 

BUbfitniHV    calle.]     Ci  I  I.nliol'l  I  Y  I.I..    or    JIM    •  which 

found   in   tin'   la 


-it-vrr 


of  all   living  plants  that 
raw     their     food     from 

Hie  BoiL  Tlii- 
coloring  matter,  chloro- 
phyll, lias  much  to  do 
with  making  the  differ- 
ent compound*  which 
go    to    make    uj>    the 

fc— Veins  In  teal  plant.      In   tin-  autumn, 

of  beetle-weed  (<;<iinr 

nphyiin,  l.i  when     the    first 

n:il     drawing     Iron 

"•*■>*)  fai]Si      the      Laws      of 

plants  lose  their  green  color,  taking  many 

Bhadd   of  red   ami   brown.     This  change  in 

color  is  an  Indication  that  their  lif« 

and  that  they  arc  of  no  more  use  to  the  plant. 

Whan   the  <lie   plant-growth   ceases   till   a 

new  crop  it  formed  in  the  spring. 

/  rw  /,•/!// ran 

/  ill  a  small  box  uith  tarth  and  in  it  plant  a  far  seeds.   After 

the  plants  haw  begun  to  g>  tftCM  M  Ml  a  box  having  an 

•i  ta  thr  Uaht  on  nttc  side  only.    After  a  Hm§  notice  how 

the  young  plants  ,trds  the  light.     Remove  the  bom  and 

the  plant*  chang-  \  and  grow  upwards. 

Questions 

1     Into  what  three  parts  may  a  plant   I  2.  What 

are  these  parta  called?    3.  How  many  of  these  parts  can  you 


44  ELEMENTS  OF  AGfclCULTURfi 

sec  on  a  young  plant?  4.  Suppose  the  roots  of  a  plant  are  cut 
off,  what  happens  to  the  plant?  5.  What  are  the  flowers,  fruit, 
and  seed  of  a  plant  called?  G.  Why  are  they  so  named? 
7.  When  a  young  plant  begins  to  grow,  do  all  oi  its  parts  grow 
in  the  same  direction?  8.  Which  part  grows  into  the  soil  and 
Which  towards  the  light?  9.  What  is  the  main  root  called? 
1*0.  What  are  its  branches  called?  11.  What  soil  of  roots  have 
turnips?  12.  What  do  we  call  roots  like  the  sweet  potato? 
1.3.  What  are  the  stems  of  trees  called?  14.  Tell  in  what  dif- 
ferent ways  the  stems  of  plants  grow.  15.  What  purpose  do 
they  serve?     16.  In  what  ways  are  all  leaves  alike? 

PROBLEM 

Make  a  list  of  all  the  plants  you  know  that  have  fleshy  roots. 
Make  a  list  of  all  the  plants  you  know  that  have  fibrous  roots. 


COMPOSITION  OF  TLANT8 

CHAPTEB  \  III.    I  oi    1'iv 

40.  Moisture. — Win  n  irreen  grass  is  cut  and 

dried  in  tin   sun  it  withers  and  dies,  losing  much  of  its 

original  weight,  ami  forms  what  is  called  hay.     If  dry 

■and  up  fine  and  caiefnllj  dried  in  an  <>\«-n  or 

0?er  a  Biol    ftre,  it   loses  -till  more  weight,  and  in  time 

becou  Uy  dry.    Plants  dried  by  the  sun  and  air 

iid  to  be  AlR-i>Kii:i>.  and  those  dried  hv  artificial 
ire  said  to  be  ciikmk  \i.i.y-i>i:ii:i>.  The  reason 
plants  lose  weight  when  they  are  dried  is  In  cause  the 
moisture  in  the  plant-  is  driven  off  hv  the  heat.  To 
prove  that  this  is  true  take  any  convenient  dish,  fill  it 
with  preen  plants,  ami  heat  it  gently  0T1  r  a  slow  fire. 
When  the  dish  heroines  thoroughly  warm  hold  Mime 
object,  such  as  a  cold,  clean  plate,  owr  it  aj 

boi  the  moisture  condenses  on  the  surfa. 

lh  grass  COt  and  dried  in  the  sun  loses  three- 
fourths  or  more  of  its  original  weight,  and  when  artifi- 
cially dried  loses  BO  per  cent  or  more  of  its  original 
farm  crops  and  trees  are  made  up  of  from 

fourths  to  four-fifths  water,  and  some  plants  con- 
tain «  much  as  90  per  r.  Different 
plants,  and  different  parts  of  the  same  plants,  contain 
different  amounts  of  water.     The  seeds  appear 

tlv  dry,  \et  if  they  are  pround  up  and  heated  they 
lose  about  one-tenth  of  their  weight,  which  is  moisture. 
Wood  when  first  cut  is  said  to  he  green,  and  though 
apparently  dry,  contains  moisture,  most  of  which  is  lost 


46  ELEMENTS  OF  AGRICULTURE. 

when  the  wood  becomes  seasoned.  Fresh  young  plants 
and  the  leaves  of  trees  contain,  large  amounts  of  water, 
75  per  cent  or  more.  The  trunks  of  trees  and  the  stems 
of  older  plants  contain  less  moisture,  usually  less  than 
50  per  cent.  Seeds  contain  less  moisture  than  any 
other  part  of  the  plant,  usually  from  10  to  20  per  cent. 

41.  Dry  Matter. — The  part  of  the  plant  that  remains 
after  it  is  dried  is  called  dry  matter,  and  makes  up, 
as  we  have  seen,  from  one-tenth  to  one-fourth  of  the 
original  weight  of  young  plants.  If  dried  plants  are 
set  on  fire  they  burn,  and  only  a  little  gray  powder  re- 
mains. This  powder  is  called  ash  or  mineral  matter. 
When  plants  are  burned,  most  of  the  dry  matter  disap- 
pears as  smoke  and  gas,  and  this  part  is  called  the 
volatile  or  combustible  matter.  The  amount  of 
dry  matter  in  different  parts  of  the  plant  depends  on 
the  amount  of  water.  The  more  moisture  a  plant  con- 
tains the  less  dry  matter,  and  the  less  water  the  more 
dry  matter. 

42.  Volatile  Matter. — This  is  the  portion  of  the  plant 
that  is  changed  into  gas  when  the  plant  is  burned,  and 
is  often  called  organic  matter.  Volatile  matter  is 
made  up  of  a  number  of  substances,  whicli  we  may 
divide  into  two  groups,  those  containing  nitrogen  and. 
those  without  nitrogen.  There  are  a  number  of  nitro- 
gen-containing substances  in  plants,  but  we  shall  call 
them  all  by  one  name,  protein.  There  are  also  a  great 
many  substances  in  the  plant  which  contain  no  nitrogen, 
and  those  we  shall  call  non-nitrogenous.  The 
amounts  of  protein  and  non-nitrogenous  substances 
vary  in  different  plants,  and  in  different  parts  of  the 


COMPOSITION  OF  PLANTS  47 

Mine  plant,  to  as  great  an  extent  as  do  the  water  and 
«Ir\  matter.  Peas,  beans,  and  clover  contain  more  pro- 
tein than  liav  or  straw.  T  and  peas 
contain  large  quantities  of  protein,  while  tin4  see 
wheal  and  corn  are  made  up  principally  of  non-nitro- 
>us  matt 

43.  Protein. — The     nitrogen-containing     substs 

of  plants  are  all  compounds  which  are  made  np  of  ftre 
element-  carbon,  hydrogen,  oxygen,  nitrogen,  and  sul- 
phur — with  sometimes  the  addition  of  very  small  quan- 
tities of  another  element  called  phosphorus.  The  first 
Lements  are  called  the  organic  elements, 
use  they  make  np  inch  a  large  part  of  all  organic 
matter.  Tlu-ir  names  are  often  abbreviated  by  writing 
limply  the  first  letter  of  the  name,  thus:  C  for  carbon, 
II  for  hydrogen,  0  for  oxygen,  X  for  nitrogen,  and  s 
for  sulphur.  These  five  letters  make  a  Word,  CHONS, 
which  may  help  one  to  remember  how  the  nitrogenous 

matter  of  plants  IS  made   Up.     There  are  a  lniml 

different  nitrogen  compounds  in  most  plants,  hut  they 

imewbat  alike,  and  WO  may  properly  call  them  by 
one  name,  protein:  jim  at  we  (all  the  inhabitant 
this  country  by  one  nan  ana.    Albumen  may  be 

mentioned  as  one  of  the  moid  valuable  compounds  that 

make  up  protein.     The  white  of  ..  pure  albumen, 

and  i-  the  iple  of  an  ;  lbuminoid. 

l'..nr  of  the  organic  elements,  C,  11.  <>.  and   X,  were 
bed  in  Chapter   III.     The  fifth  element  is  8UL- 

iMItli. 

44.  Sulphur. — This  element  is  a  solid  substance,  and 
is    probably    hetter    known    as    brimstone.      Sulphur   is 


48  ELEMENTS  OF  AGRICULTURE 

widely  distributed  both  in  the  vegetable  and  mineral 
kingdoms;  all  plants  contain  sulphur,  and  it  occurs  in 
large  deposits  in  some  parts  of  the  earth.  When  eggs 
decay  the  sulphur  in  the  protein  unites  with  hydrogen 
and  forms  a  gas  called  hydrogen  sulphide,  which  has  a 
very  disagreeable  odor.  It  is  the  formation  of  this  gas 
that  makes  decaying  eggs  so  disagreeable. 

45.  Non-Nitrogenous  Compounds. — In  all  plants 
there  are  a  number  of  organic  compounds  that  contain 
no  nitrogen;  such  compounds  are  largely  carbohy- 
drates. They  are  made  up  of  carbon,  hydrogen,  and 
oxygen.  The  word  carbohydrate  means  carbon  com- 
bined with  hydrogen  and  oxygen  in  the  proportion  to 
form  water.  The  Greek  word  for  water  is  Uydor,  so  we 
speak  of  a  substance  combined"  with  water  as  a 
hydrate.  Here  we  have  carbonhydrate  or  carbohy- 
drate. Starch,  sugar,  gum,  and  woody  matter  (cellu- 
lose) are  all  substances  containing  no  nitrogen,  and 
are  made  up  of  C,  H,  and  0.  They  are  consequently 
carbohydrates.  These  four  compounds  make  up  a  large 
part  of  all  plants,  and  are  found  in  varying  quantities 
in  different  plants  and  different  parts  of  the  same  plant. 
Sugar  is  found  in  the  stem  of  sugar  cane  and  sorghum, 
in  the  roots  of  sweet  potatoes  and  beets,  in  the  fruit  of 
many  plants,  and  small  quantities  are  found  in  the  seed? 
of  most  plants.  Starch  is  found  in  the  leaves  of  trees 
and  the  stems  of  young  plants,  in  the  roots  of  many 
plants,  notably  the  sweet  potato,  and  in  the  tubers  of 
the  Irish  potato.  The  grains  of  many  seeds  contain 
quantities  of  starch;  corn  and  wheat  contain  about  70 
per  cent  starch.    Woody  matter  makes  up  the  stem  and 


COMPOSITION  OF  PLANTS  49 

bark  of  most  plants.  Besides  the  carbohydrates,  fat  or 
oil  is  found  in  plants,  principally  in  the  seeds:  for  in- 
stance tin  iil  bean  and  cottonseed 

/  IPBBIM1  I  / 

tOm*  frrsh   ,/ni.ss;  „  ,  i,/h   it  and  dry  it   in  Hie  8Utl.     After 

■  <i  u<mh  in/iiin  and  notiir  hou    much   it  has  lost  in  weight. 

■  t   it  on  fin    and  allon    it   to  hum;   ucujh   the  ash.     < 
lute  tlo  of  both  moisture  and  unit 

Questions 

1.   I I.»w   i-   hay   formed?     2.  Why  docs  hay  weigh  less  than 
ia.*s   from   which    it  was  cut?     3.  What    happen*   to  hay 
when  healed   by   I  Ahich  contains  the  more  moisture,  a 

plant  01  it*  seed?  5.  \N  hen  noflotVI*  i*  dried  <>'U  from  I  plant, 
what  is  tin-  remainder  called  J  ti.  How  i>  dry  matter  made  up  | 
7.  That  part  «»f  a  plant  which  disappear-*  win  n  the  plant  i* 
l.urned  i>  called  what  t  S.  Into  what  two  classes  of  substances 
can  OTfaak  matter  he  divided  '  9.  Of  what  live  elements  is  the 
nitrogenous  matter  of  plant*  made  up?  10.  What  are  these 
five  elements  called?  11.  In  what  parts  of  the  p'ant  is  protein 
usually  found?  \1.  dive  an  example  of  a  nitrogenous  sub- 
stance. 1.1.  What  are  the  best  known  non-riitrogenous  sub- 
found  in  plants?  14.  What  three  elements  make  up 
carbohydrates  T 

PRoid.l 

1 .   If  n  certain  hay  contain-  in  per  cent  of  water,  how  many 
pounds  of  dry  matter  does  a  ton  of  such  hay  contain? 

v.     hundred    pounds   of   corn   contains   350   pounds   of 
starch,  what  is  the  per  cent  of  starch  T 

i\c  hundred  pounds  of  oats  contains  50  pounds  of  pro- 
tein, calculate  the  per  cent  of  proU-iu. 


50  ELEMENTS  OF  AGRICULTURE 


CHAPTER  IX.— Composition  of  Plants 
-(  Continued  ) 

46.  Mineral  Matters  or  Ash. — The  ashes  of  plants  are 
made  up  of  a  number  of  elements,  which  are  combined 
into  various  compounds.  Of  ihe  organic  elements,  car- 
bon, oxygen,  sulphur,  and  phosphorus  are  often  found 
in  the  ashes  of  plants  and  sometimes  nitrogen  and 
hydrogen.  Besides  these  elements  the  ash  contains  sili- 
con, chlorine,  potassium,  sodium,  calcium,  magnesium, 
iron,  manganese,  and  minute  quantities  of  several  other 
elements.  These  elements  are  all  combined  in  various 
ways  with  each  other,  none  of  them  being  found  alone. 

47.  Phosphorus. — This  element,  which  is  a  solid  sub- 
stance, has  such  a  tendency  to  combine  with  oxygen  that 
it  is  never  found  alone.  Ordinary  phosphorus  must 
be  kept  under  water  to  prevent  its  oxidizing.  When 
phosphorus  and  oxygen  unite,  the  union  produces 
much  heat,  and  this  fact  is  taken  advantage  of  in  the 
manufacture  of  matches.  Phosphorus  is  usually 
found  combined  with  calcium  and  oxygen,  in  which 
form  it  is  variously  called  calcium  phosphate,  phos- 
phate of  lime,  and  bone  phosphate.  This  compound 
makes  up  a  large  part  of  the  phosphate  deposits  of  the 
wrorld.  Some  form  of  phosphorus  exists  in  the  bodies 
of  all  plants  and  animals,  and  neither  can  grow  without 
a  supply  of  this  element.    The  combined  phosphorus  in 


COMPOSITION  OF  PLANTS  51 

and   plants   is  usually  spoken  of  I  iioric 

ACI1>. 

48.  Silicon. — This  is  a  solid  element,  which,  MB- 
bined  with  oxygen,  makes  sand,  or  quartz  rock.    Silicon 

occurs  fr»c,  hut  always  combined  with  some  other 
clement,  usually  axjgUL  Its  compounds  are  called 
silk  unbilled  with  ind  other  elements, 

notably  potassium  and  sodium,  it  is  found  in  the  ashes 
of  plants. 

49.  Chlorine. — This  element  is  a  gas  with  a  very  dis- 
agreeable odor.  It  is  very  active,  combining  readily 
with  many  other  elements.  With  sodium  it  forms  >alt, 
which  is  widely  distributed  over  the  earth.  Compounds 
of  chlorine  with  other  elements  are  called  OHIOBTOU, 
and  they  are  found  in  the  ashefl  of  all  plants. 

50.  Potassium. — Thia  i-  a  -olid  element,  which  al- 
0CC11XI   in  combination.      It   eondtines  very   readily 

with  water,  and  forms  what  we  know  as  i,\\:  or  PO  i  MH 
LTK.      It   ftJSO  combines  with  chlorine,   forming  a 
pound  resembling  salt  and  known  as  potassitm  <  hlo- 

i.iim:.  commonly  called  kuriavi  or  potash.    Od  the 

farm   mil  compound   is  much   used  as  a    fertilizer.      It 
combines   with   nwgen  and  carbon   to   form    i 
nmt»'\\i,        !  fotm  it  is  found  in  the  ashes  of 

all  pi; 

51.  Sodium. — This  is  another  solid  element,  which 
closely  resembles  potassium.  It  never  occurs  free,  hut 
always  in  combination.  It  forms  compounds  very  simi- 
lar to  those  formed  by  potassium.  With  water  it  forms 
soda  lyk;  with  rhlor  ;  and  with  carhon  and 
oxygen,  sodium  carbonate.    It  occurs  in  some  form  in 


52  ELEMENTS  OF  AGRICULTURE 

the  ashes  of  all  plants.  Wood  ashes  are  often  leached 
with  water  and  the  compounds  of  potassium  and  sodium 
which  dissolve  out,  form  common  lye,  which  is  used  to 
make  soap. 

52.  Calcium. — A  solid  element  which  never  occurs  in 
a  free  state,  but  always  combined  with  some  other  ele- 
ment. With  carbon  and  oxygen  it  forms  a  compound 
which  is  properly  known  as  calcium  carbonate. 
When  this  compound  is  heated  very  hot  the  carbon  and 
part  of  the  oxygen  are  driven  off  as  carbon  dioxide,  and 
the  calcium  and  part  of  the  oxygen  remain  as  quick 
lime..  Quick  lime  takes  up  water  very  rapidly  and 
changes  to  slacked  lime.  Calcium  in  some  form  is 
found  in  the  ashes  of  all  plants. 

53.  Magnesium. — This  element  is  a  metal  of  a  light 
silver  color.  It  unites  with  oxygen  when  heated,  and 
the  union  gives  a  very  brilliant  light,  known  as  magne- 
sium light.  This  light  is  used  for  making  photographs 
at  night,  and  the  magnesium  used  for  this  purpose  is 
called  flashlight  powder.  In  the  ashes  of  plants 
magnesium  always  occurs  combined  with  some  other  ele- 
ment, and  never  as  a  metal. 

54.  Iron. — This  element  is  so  well  known  that  it 
scarcely  needs  a  description.  It  is  found  in  the  ashes  of 
all  plants  combined  with  some  other  element.  The 
green  coloring  matter  of  plants  contains  iron. 

55.  Manganese. — This  is  a  metal  that  somewhat  re- 
sembles iron.  It  is  seldom  found  alone,  but  usually  in 
combination  with  oxygen.  Its  compounds  are  similar 
to  those  of  iron,  and  occur  in  small  Quantities  in  the 
ashes  of  all  plants. 


COMPOSITION  OF  PLANTS 


53 


Minute  quaiititi. i  «.f  a  Dumber  of  other  eleroenti  are 
found  iii  thi  isbefl  of  plants,  l»ut  they  are  of  no  im- 
portance in  agriculture,  and  need  not  be  mentioned. 

The  following  diagram  shows. in  a  condensed  form 
the  plant  is  built  up: 


,  Moisture 


Plniit 


(TttrafSOOOl    Matt.r- Plot,  in 
(Albuminoid.  ! 


Volatll.- 


Nitroge- 
nous Matter 


Wood 

Qojh 

041 

(  ll\<lrogelt 


Carbon 

•  <en 

Nitrogen 
Sulphur 
(Phosphorus) 


Oufcoa 

Hydrogen 


Matter 


Non- Volatll.  .Mmt.i  or  Ash 


'Phosphorus 


s.-lluin 

Iron 
Chlorine 


MngHMM 

MOfMaUnt 


54  ELEMENTS  OE  AGRICULTURE 


Questions 

1.  In  what  form  are  elements  found  in  plants?  2.  Name 
twelve  elements  that  make  up  most  of  the  compounds  in  plant 
ashes.  3.  Is  phosphorus  a  liquid,  solid  or  gas?  4.  What  house- 
hold article  is  made  up  in  part  of  phosphorus?  5.  With  what 
two  elements  is  phosphorus  usually  found  combined,  and  what 
is  the  compound  called?  6.  When  silicon  is  combined  with 
oxygen,  what  is  formed?  7.  What  are  compounds  containing 
chlorine  called?  8.  In  what  combinations  is  potassium  found? 
9.  Describe  another  element  that  resembles  potassium.  10.  De- 
scribe calcium.  11.  What  is  the*  compound  of  calcium  with 
oxygen  called? 


I  -« •<-•!»    I  H  I    11  \  n  I    I  \  K  IS  FBOM  THB  SOIL  55 


CHAPTBB    V     'I'm:   HVKJO  tin:    Piwr  T\m> 
the  Soil 

56.  Water. — Most  plants  have  only  two  sources  from 
which  to  draw  their  food — namely,  the  soil  and  the  air. 
From  which  of  these  BOTOI  do  tlu-v  draw  their  water? 
Seed  will  i»>t  Bproid  in  i  perfectij  dry  soil.  Deserts 
produce  almoe4  no  plants,  and  in  time  of  continued 

•  iron-lit  planfl  droop  and  finally  die     It  is  evident  that 

soil  to  sprout  seed  and  grow  plants  must  contain  water; 

and   from  these   facts   we  learn   that   plants  draw  their 
water  supply  from  the  soil. 

]\\  remembering  that  about  78  per  cent  of  meal 
young  plants  m  moisture,  we  may  form  some  idea  of  the 
vast  amount  of  water  taken  from  the  soil  by  many 
crops.  Suppose  an  acre  (,f  groan  prodncei  a  crop  of 
green  dorer  weighing  12,000  pounds,  or  6  tons;  about 
80  per  cent  of  this  is  water,  or  i),600  pounds  or  4.8  ton?. 
But  ttufl  i-  not  all  the  water  an  acre  of  clover  requires 
while  it  is  growing.  You  may  drink  a  glass  of  water  in 
the  morning,  hut  in  a  few  hours  you  are  again  thirsty 
and  want  more  water.  So  with  the  clover;  it  is  con- 
stantly drinking  more  water,  and  if  not  supplied  the 
crop  withers  and  in  time  ,;  >v,  what  becomes  of 

all   the   water   which    plants   drink   Dp    from    the  soil? 
i  can  hold  only  a  certain  amount,  and  as  tlu 

constantly  drinking  it  in,  boom  must  !>*•  given  oft.    If 

you  will  i  .fully  tl  of  plants  you  will 


56 


ELEMENTS  OF  AGRICULTURE 


find  that  the  upper  side,  which  is  the  one  turned  towards 
the  sun,  is  different  from  the  lower  side.  By  examining 
the  lower  side  with  a  good  magnifying  glass  you  will 
notice  many  small  openings  in  the  leaf.  These  little 
mouth-like  openings  are  called  stomata,  and  have  the 
power  of  opening  or  contracting.     Fig.  10  shows  some 

of  these  stomata.  Through 
these  openings  the  plant 
gives  off  water  and  takes  in 
food  from  the  air.  Water 
thus  given  off  by  the  plant 
is  said  to  be  exhaled.  The 
plant  takes  in  or  absorbs 
water  through  its  roots  and 
exhales  it  through  its 
leaves.  This  giving  off  of 
water  through  the  leaves  is 
also  called  transpiration, 
and  may  be  compared  to 
the    giving    off    of    water 

Fig.  10.— Stomata,  or  breathing  +lirmio.li  fho  «Vin  nf  Vmrnin 
pores :  A,  under  side  of  leaf  highly  tUlOUgll  tne  SKm  01  Human 
magnified;  stomata  shown  at  «;    i •    _        i  •   i     •      „„n   j   L^_ 

small  hairs  in  leaf  at  h.  beings,  which  is  called  per- 

B,  section  through  stomata,  ...             mi                       .       «. 

highly  magnified;   8,  mouth  of  SpiratlOn.       Ihe    amount    01 

stomata;  a,  air  space  in  the  loaf;  ,  . 

0,  cells  which  as  they  expand  or  water      which      plants      give 

contract,   open  or  close    the  sto-  t             ° 

mata.  off    through    their    leaves, 

of  course,  varies,  but  most  growing  crops  give  off 
large  quantities  of  water.  On  a  dry,  hot  day  grass 
plants  have  been  known  to  exhale  their  own  weight  of 
water  in  twenty-four  hours.  Experiments  conducted  in 
Germany  have  shown  that  plants,  for  every  pound  of 
dry  matter,  require,  during  the  time  they  are  growing, 


FOOD  THE  PLANT  TAKE8  FROM  THE  SOIL  57 

about  the  following  amounts  of  water:  Oats,  376  pounds 
of  water  to  one  pound  of  dry  matter;  wheat,  338  pounds 
of  water  to  one  pound  of  dry  matter;  red  clover,  310 
pounds  of  water  to  one  pound  of  dry  matter.  Take  as 
an  example  the  clover  crop  already  mentioned,  which 
weighed  12,000  pounds.  As  80  per  cent  of  this  is 
.  we  have  20  p  dry  matter,  or  2,400  pounds. 

If  one  pound  of  dry  matter  requires  310  pounds  of 
<>0  pounds  must  require  Mi.ooo  pounds 
of  water,  or  3T2  tons,  or  about  75,000  gallons.  At  this 
rat.-,  to  produce  about  one  ton  of  clover  hay  more  than 
300  tons  of  water  are  needed. 

The  moisture  in  the  atmosphere  cannot  be  taken  up 
by  plants  unless  it  first  pttsei  into  (he  soil. 

A  plant  wilts  because  the  leaves  give  off  more  water 
than  the  root-  can  Supply. 

57.  Nitrogen. — From  the  soil  plants  draw  most  of 
their  supplies  of  nitrogen  which  is  combined  in  the 
organic  matter  of  the  soil.  Nitrogen,  if  not  the  most 
important,  of  the  mo<t  important  of  all  the 
plant  fuels,  and  we  shall  have  more  to  say  about  it  when 
we  come  to  write  of  soils. 

58.  Mineral  Matter. — The  elements  which  make  up 
the  ashes  of  planti  come.  .  .  from  the  soil,  as 

found  in  the  atmosphere  or  largely  in 
water.  Although  the  amount,  of  mineral  matter  con- 
!  in  pkntl  is  very  small,  a  proper  supply  is  abso- 
lutely necessary.  All  soils  contain  the  necessary  ele- 
of  plant  food,  but  in  many  soils  the  supply  is 
small,  and  in  some  soils  the  elements  are  so  combined 
as  to  be  unfit  for  plant  food.     When  such  is  the  case 


58  ELEMENTS  OF  AGRICULTURE      . 

they  are  said  to  be  unavailable.  For  instance,  nitrogen, 
which  makes  up  four-fifths  of  the  air,  is  a  very  im- 
portant plant  food,  but  plants  cannot  take  in  free  nitro- 
gen gas;  it  must  first  be  combined  with  some  other  ele- 
ments, usually  hydrogen  and  oxygen,  before  it  can  be- 
come plant  food.  Phosphorus  is  another  valuable  plant 
food,  and  when  combined  with  certain  quantities  of 
calcium  and  oxygen,  is  readily  taken  up  by  plants,  but 
alone  or  combined  with  larger  quantities  of  calcium 
and  oxygen  it  is  not  fit  for  plant  food. 

Nitrogen,  phosphorus,  and  potash  are  three  im- 
portant foods  that  the  plant  takes  up  from  the  soil.  A 
proper  supply  of  these  foods  is  often  lacking  in  soils,  so 
they  are  added  in  the  form  of  fertilizers.  Iron  is  an- 
other important  plant  food.  It  is  necessary  for  the  for- 
mation of  chlorophyll,  the  green  coloring  matter  of 
plants,  which  utilizes  the  carbon  dioxide  of  the  air  in 
the  formation  of  starch.  As  all  soils  contain  a  great 
abundance  of  iron  it  is  not  necessary  to  add  it  as  a  fer- 
tilizer. Calcium  is  still  another  important  plant  food. 
Soils  usually  contain  an  abundant  supply  of  this  ele- 
ment, but  it  is  sometimes  found  necessary  to  add  it  to 
the  soil  in  the  form  of  lime.  These  foods — nitrogen, 
phosphoric  acid,  potash,  lime,  and  iron — are  necessary 
to  the  growth  of  plants,  and  no  crop  can  be  grown  with- 
out a  proper  supply  of  them.  Nitrogen,  phosphoric 
acid,  potash,  and  lime  are  the  four  most  often  lacking 
in  soils,  and  to  make  up  any  deficiency  they  are  added 
in  the  form  of  fertilizers. 


POOD  THE  PLANT  TAKES  PROM  TUB  SOIL  59 


Questions 

1.  From  what  two  sources  <!<•  plants  draw  their  food? 
2.  What  will  become  of  a  seed  in  a  perfectly  dry  soil? 
.'{.  Where  do  plants  get  their  water?  4.  What  per  cent  ofl 
|WHrlag  plants  is  water?  5.  What  becomes  ot  the  excess  of 
tik. ii  bj  the  plant?  t>.  How  is  this  water  given  offl 
7.  What  is  this  pllllKSS  call. -.I-:  B.  What  an-  thfl  npenings  in 
Where  .I.ms  tlw  mineral  matter  in  plant- 
MM  flWBl  l&  I'r«'in  what  snnrco  <loes  a  pinnt  draw  ni..-t  <•( 
it-,  sltrOgSBl  11.  W  hal  supplies  mineral  nia.ter  for  plant-' 
If,   What    is   .l)l..r..phyll?      13.   Why   an-    f.rt  ilUsfl   SOOMl  ini.s 

added  to  soils?     II.   W  hen  are  planl    f Is  Mid  t<»  be  un 

nble?     l.">.  W  h.  ii  an   plant  foods  said  to  be  available? 

PROBLEM 

If  a  crop  of  oats  contains  1,000  pounds  of  dry  matter,  about 
how  many  pounds  of  water  has  Um  SflOB  used  during  the  time  it 
was  growing? 


60  ELEMENTS  OF  AGRICULTURE 


CHAPTER  XI.— The  Food  the  Plant  Takes  from 
the  Air 

59.  Carbon. — Plants,  as  you  have  seen,  get  their  water 
and  mineral  matter  from  the  soil.  You  would  then 
naturally  inquire  whether  plants  get  their  carbon  from 
the  soil.  Carbon  in  some  form  is  present  in  all  soils,  but 
plants  do  not  use  this- carbon  for  food.  It  has  been 
proven  by  experiments  that  plants  cannot  grow  unless 
their  leaves  are  supplied  with  air  containing  carbon 
dioxide  gas,  which  you  remember  makes  up  a  small  part 
of  the  atmosphere.  Other  experiments  have  shown  that 
the  leaves  of  plants  absorb  carbon  dioxide  from  the 
air,  take  from  the  gas  the  carbon,  and  give  off  the 
oxygen.  Men  and  animals  reverse  this  process;  they 
draw  air  into  their  lungs,  where  the  oxygen  of  the  air 
unites  with  the  carbon  in  the  blood,  and  is  given  off  as 
carbon  dioxide  gas.  Men  and.  animals  inhale  oxygen 
and  exhale  carbon  dioxide.  Plants  inhale  carbon  dioxide 
c^nd  -give  off  oxygen.  Animals  cannot  live  in  air  con- 
taining much  carbon  dioxide.  Plants  cannot  live  with- 
out a  supply  of  this  gas..  Leaves  have  often  been  called 
the  lungs  of  plants,  and  in  their  manner  of  taking  up 
food  from  the  air  they  do  resemble  the  lungs  of  animals. 
Breathing  animals  are  constantly  adding  to  the  supply 
of  carbon  dioxide  in  the  air ;  the  leaves  of  plants  are  con- 
stantly absorbing  it  and  returning  to  the  air  free  oxy- 
gen.    In  this  way  plants  aid  in  maintaining  a  balance, 


FOOD  THE  PLANT  TAKES   FKOM  THE   AIR  fil 

which  means  that  the  amount  of  carbon  dioxide  in  the 
air  remains  always  about  the  same. 

The  leaves  of  plants  absorb  carbon  dioxide  only  in 
direct  sunlight;  on  cloudy  days  the  amount  of  gas  ab- 
sorbed is  small,  and  at  night  the  plant  not  only  does 
not  absorb  any  gas,  but  actually  gives  off  carbon 
animals  do  in  breathing.  The  amount  of 
carbon  dioxide  thus  given  off  is,  however,  very  small 
compared  with  what  is  taken  np  under  the  influence  of 
light 

60.  Oxygen. — While  the  leaves  of  plants  under  the 
Influence  of  sunlight  take  up  carbon  dioxide  and  give 
off  oxygen,  the  roots  of  growing  plants  require  a  con- 
stant supply  of  free  oxygen  in  order  that  they  may 

Seeds,  you  remember,  require  a  supply  of  air 
before  they  will  sprout,  and  it  is  the  oxygen  of  the  air 
that  enables  them  to  begin  to  grow.  A  seed  supplied 
with  only  nitrogen  gas  will  not  sprout,  no  matter  how 
t  the  other  conditions.  When  plants  are  in  bloom, 
and  later  on  when  they  are  forming  seed,  a  constant 
supply  of  oxygen  is  necessary.  Oxygen  is  then  neces- 
sary for  all  growing  plants  from  the  beginning  of  their 
life  to  the  end.  The  air,  of  course,  contains  an  abundant 
supply  of  oxygen  for  all  the  needs  of  the  plant  above 
ground — that  is,  for  the  buds,  flowers,  and  leaves.  The 
spaces  in  soils,  as  you  will  presently  learn,  contain  air, 
which  supplies  >ts  of  plants.    If  for  any 

reason  the  supply  of  air  in  the  soil  becomes  exhf 
the  plant  growth  is  checked 

61.  Ammonia  Gas. — Air  contains  minute  quantities 
of  this  gas,  which  supplies  to  plants  a  small  part  of 


62  ELEMENTS  OF  AGRICULTURE 

their  nitrogen.  This  gas  is  not  taken  up  through  the 
leaves  or  stem,  but  through  the  roots.  Rain  water 
washes  the  ammonia  from  the  air  into  the  soil,  where 
it  may  be  changed  to  a  form  suitable  for  plant  food. 
The  amount  of  nitrogen  thus  supplied  to  plants  is,  how- 
ever, quite  small. 

62.  Nitrogen. — Some  plants  have  the  power  of  using 
the  nitrogen  of  the  air  for  food.  There  are,  however, 
only  a  few  varieties  of  plants  that  have  this  power,  and 
of  them  we  shall  have  more  to  say  later  on. 

Questions 

1 .  From  what  source  do  plants  draw  their  supply  of  carbon  ? 
2.  How  does  carbon  occur  in  the  air?  3.  In  what  form  is  car- 
bon taken'in  by  plants?  4.  In  breathing,  what  element  is  taken 
from  the  air  by  men  and  animals,  and  what  returned  to  it? 
5.  What  element  is  taken  from  the  air  by  the  leaves  of  plants, 
and  what  returned?  6.  Why  are  the  leaves  sometimes  called 
the  lungs  of  plants?  7.  Why  is  it  necessary  to  loosen  up  the 
giound  when  planting  seed?  8.  What  parts  of  plants  take  up 
oxygen?  9.  Does  the  air  supply  plants  with  any  part  of  their 
nitrogen  ? 


llou    PLANTS  GUOW  63 


CHAFTSB  Ml.     Ho*  Plants  Grow 

63.  Water  Enters  the  Plant  Through  Its  Roots.— We 
learned  in  thetlast  chapter*  what  kind  of  food 

plant-  require  and  where  they  get  it.    Now  the  qu 

.  ilou  doei  the  plant  take  up  its  food  from  the 
soil  and  air?  Through  its  roots  and  leaves,  of  course, 
but  how?  The  roots  have  the  power  of  sucking  the 
moisture  from  the  soil,  through  their  root  hairs,  as  de- 
scribed OH  pap  59,  Each  little  root  hair  is  a  minia- 
ture well  fnmi  which  the  water  rises  into  the  plant. 

64.  Mineral  Matter  Enters  the  Plant  Through  Its 
Roots. —  Ifoal  of  the  mineral  matter  in  the  soil  is  in  the 
form  of  solids,  and,  before  it  can  enter  the  plant,  must 
be  dissolved.  Under  the  head  of  leaching  yon  were  told 
how  rain  water  dissolves  various  substances  in  the  soil 
and  carries  them  olT  to  the  sea.  The  water  which  the 
roots  of  plants  take  in  »  "iitains  dissolved  in  it  much 
mineral  matter,  usually  in  the  form  of  salts.     In  this 

the  plant  can  drink  in  its  food  dissolved  in  water. 
But  not  all  of  the  mineral  matter  is  taken  up  by  *he 
plant  in  this  manner.  All  plants,  you  know,  contain  a 
liquid  called  sap.  No  doubt  you  have  all  seen  it  oozing 
out  of  a  cut  in  some  tree  or  plant.  The  sap  which  goes, 
down  into  the  roots  can  dissolve  some  minerals  which 
cannot,  and  it  acts  on  the  small  fragments  of 
mineral  with  which  the  root  hairs  come  in  contact  Fig. 
8,  page  41,  shows  how  the  root  hairs  are  covered  by  fine 
particles  of  mineral  matter,  which  are  being  dissolved 


64  ELEMENTS  OF  AGRICULTURE 

by  the  sap.  Oxygen  is  also  taken  up  by  the  roots  of 
plants,  and  nitrogen  compounds  dissolved  in  water  also 
enter  the  plant  through  its  roots. 

65.  Compounds  are  Manufactured  in  the  Leaves. — 
Through  their  leaves  plants  draw  from  the  air  supplies 
of  carbon  dioxide;  through  their  roots  they  pump  water 
and  the  salts  it  contains  in  solution;  and  from  these 
compounds  are  made  many  substances  that  go  to  build 
up  plants.  Chief  among  these  is  starch,  a  substance 
with  which  every  child  is  familiar,  as  it  makes  up  a  laryj 
part  of  many  foods;  wheat  flour,  corn  meal,  rice,  and 
potatoes  are  mostly  starch,  every  grain  of  which  is 
manufactured  in  the  leaves  of  the  plant  which  grows 
them.  The  so-called  starch  factories  of  the  world  never 
make  an  ounce  of  starch.  All  they  can  do  is  to  separate 
from  the  other  substances  with  which  it  is  mixed  the 
starch  that  is  actually  made  in  the  leaves  of  plants, 
and  afterwards  concentrated  in  the  seed,  root,  or  stem. 
The  real  starch  factories  are  the  green  leaves  of  plants. 
Starch  is  made  up  of  carbon,  hydrogen,  and  oxygen — 6 
parts  of  carbon,  10  parts  of  hydrogen,  and  5  parts  of 
oxygen,  or,  as  the  chemist  writes  it,CeHioOs.  Carbon 
dioxide  the  chemist  writes  CO 2,  two  parts  of  oxygen  to 
one  of  carbon;  and  water  he  writes  HOs,  two  parts  of 
hydrogen  to  one  of  oxygen.  It  is  evident  that  these  two 
compounds  contain  all  the  elements  necessary  to  form 
starch,  and  it  is  from  them  that  the  plant  manufactures 
it.  But  how?  We  may  mix  water  and  carbon  dioxide 
in  varying  proportions  and  under  all  sorts  of  conditions, 
but  no  starch  results;  we  may  mix  six  parts  of  carbon, 
ten  parts  of  hydrogen,  and  five  parts  of  oxygen,  and 


HOW  PLANTS  GROW  65 

subject  Umbo  to  all  sorts  of  conditions,  but  no  starch 
.\n  (ii.miM.  bowerei  skillful,  has  ever  suc- 
d  in  making  starch.  But  the  simplest  Little  plant 
thai  grows  knows  the  process,  ami  every  day  in  spring 
and  rammer,  irhen  the  sun  shines,  is  busy  producing  this 
useful  substance.  The  chlorophyll  in  the  green  Leaves 
of  plants  i>  the  starch  manufacturer,  the  leaf  is  the  fac- 
tory, ami  ranllght   its  power.     When  the  waves  of  Min 

light  strike  on  the  surface  of  green  leaves  the  chloro- 
phyll is  busy  converting  water  and  carbon  dioxide  into 

starch;  when  the  sunshine  ceases  the  chlorophyll  stops 
work.  But  starch  is  not  the  only  substance  that  is 
formed  in  plants.  Sugar,  oil,  woody  matter,  protein, 
ami  various  other  compounds  are  likewise  formed  in 
the  plant.  No  one  knows  exactly  how  these  various 
Compounds  are  formed  in  the  plant,  hut  it  is  very  pro- 
bable that  most  of  them  are  formed  in  the  leaf  under 
the  influence  of  sunshine.  The  various  carbohydrates 
are  probably  made  from  starch.  The  protein  com- 
pound s  carbon,  hydrogen  and  oxygen,  contain 
nitrogen  and  sulphur,  which  elements  are  drawn  from 
the  soil.  But  as  to  just  how  they  are  made  into  the 
various  compounds  found  in  plants  we  do  not  at  ]  : 
know. 

66.  Sap  and  Its  Work. — The  compounds  formed  in 
the  leaves  of  plants  are  distributed  by  the  sap  to  various 
pari-  of  the  plant  I  PS  needed  to  huild  it  up.     As 

the  plant  growl  older  it-  various  parts  change  in  compo- 
sition.    The  stems  of  most  young  plants  contain  starch, 
sugar,  and  nitrogenous  substances,  which,  as  the  plant 
6 


66  ELEMENTS  OF  AGRICULTURE 

grows  older,  are  found  concentrated  in  the  seed,  and 
the  stem  is  then  composed  a] most  entirely  of  woody 
matter. 

EXPERIMENTS 

Over  a  patch  of  green  grass  place  a  box  or  any  other  covering 
to  exclude  the  sunlight.  In  a  feiv  days  the  grass  oegins  to  lose 
its  color  and  in  time  becomes  white.  If  exposed  to  the  sun  again 
it  in  time  regains  its  color  and  continues  to  grow. 

Select  a  growing  leaf  of  bright  green  color,  and  without  taking 
it  from  the  plant  cover  a  portion  of  the  surface  exposed  to  the 
light  with  black  paper.  The  paper  may  be  pinned  or  sewed  on 
and  should  fit  close  enough  to  cut  off  all  the  light.  In  time  the 
portion  of  the  leaf  under  the  paper  loses  its  color,  turning 
white.  By  cutting  the  paper  into  proper  shapes,  figures  or  let- 
ters may  be  formed  on  the  leaf. 

Questions 

1.  Haw  do  plants  take  up  water  from  the  soil?  2.  How  do 
plants  take  up  their  mineral  food  from  the  soil  ?  3.  What  is 
the  juice  found  in  the  stems  of  plants  called  ?  4.  In  what  way 
does  sap  aid  in  the  growth  of  a  plant?  5.  In  what  form  does 
the  plant  take  its  food  from  the  air?  6.  What  well  known 
substance  is  formed  in  the  leaves  of  plants?  7.  Of  what  is 
starch  formed?  8.  How  are  the  compounds  formed  in  the 
leaves  distributed?  9.  Are  all  parts  of  plants  of  the  same 
composition?  10.  As  the  plant  grows,  in  what  respect  does  it 
change  in  composition?  11.  Where  is  much  of  the  plant  food 
finally  concentrated? 


HOW  SOILS  ABE  MADE  6? 


PART  III.-Soils 


CHAPTER  XIII.— How  Soils  are  Made 

67.  General  Definition  of  Soils. — Many  persons  im- 
properly speak  of  soil  as  "dirt."  Soil  may  be  defined 
as  the  finely  pulverized  portions  of  the  earth's  surface 
in  which  plants  may  grow.  Dirt  means  something  un- 
clean or  filthy,  and  the  word  should  never  be  applied  to 
soil.  Soil,  it  is  true,  may  become  dirty,  but  fresh,  pure 
soil  is  clean  and  destroys  dirt  tad  filth. 

Soil,  as  the  word  is  ordinarily  used,  refers  to  only  the 
first  G  to  l£  inches  of  the  earth's  surface.  The  portion 
below  this  depth  is  call. d  the  SUBSOIL.  There  is  usually 
a  marked  difference  between  the  soil  and  subsoil. 

Land  is  made  op  of  soils,  rocks,  stones,  and  beds  of 
mineral  ore.  ft  dn  are  the  great  beds  of  hard  minerals 
which  may  often  be  seen  projecting  through  the  soil 
and  sometimes  making  up  whole  mountain  ranges.  Beds 
of  granite,  marble,  sandstone,  and  limestone  are  called 
rocks. 

Scattered  through  the  soil  are  coarse,  broken  frag- 
ments of  the  rock  masses  called  stones.  Rocks  and 
stones  are  made  up  almost  exclusively  of  mineral  mat- 
id  when  they  decay  they  form  soils.  It  is  hard  to 
realize  that  the  surfaces  of  rocks,  which  appear  to  be 
almost  everlasting,  are  constantly  being  worn  away  to 


68  ELEMENTS  OF  AGRICULTURE 

form  soils,  but  such  is  undoubtedly  the  case.  If  a  soil  is 
examined  with  a  good  magnifying  glass  it  is  found  to  be 
made  up  of  many  small  fragments  of  various  shapes  and 
sizes.  The  fragments  resemble  those  which  are  formed 
when  a  coarse  stone  is  pulverized,  and  this  is  just  what 
has  happened.  Coarser  fragments  of  stone  have  been 
broken  up  by  various  agencies,  and  the  small  particles 
resulting  have  formed  the  soil.  We  may  put  it  down 
as  an  accepted  fact  that  the  mineral  matter  of  all  soils 
has  resulted  from  the  breaking  up  of  rocks  and  stones. 

68.  Formation  of  Mineral  Fragments  in  Soils. — -Now, 
how  is  it  that  these  apparently  indestructible  rock 
masses  have  been  so  broken  up  as  to  form  the  great  soil 
areas  of  the  world?  Soils  are  formed  so  slowly  and 
quietly  that  we  are  not  aware  that  such  a  work  is  going 
on  about  us,  but:  soils  are  forming  to-day  just  as  they 
have  been  for  thousands  of  years.  The  great  soil-maker 
of  the  world  is  water,  and  it  lias  several  different 
methods  of  making  soil. 

69.  Mechanical  Action  of  Water. — More  soils  are 
formed  by  the  mechanical  action  of  water  than  by  any 
other  agency,  so  we  may  best  consider  it  first. 

The  surfaces  of  all  rocks,  however  smooth  appa- 
rently, are  filled  with  minute  cracks.  The  surfaces  of 
rocks  long  exposed  to  the  weather  are  particularly  full 
of  irregularities;  an  apparently  smooth  rock,  if  exam- 
ined with  a  magnifying  glass,  will  show  many  cracks  and 
joints.  Into  these  cracks  and  joints  water  penetrates, 
and  if  the  temperature  becomes  low  enough,  the  water 
freezes,  the  cracks  become  enlarged,  and  often  pieces  of 
rock  break  off.     Water  always  expands  when  freezing, 


now  soils  aue  li  69 

md  the  force  exerted  ii  tn  mendo    .    >trong  glass  bot- 
tles arc  barsl  by  freeaing  water,  end  even  iron  r< 
art   barn  to  jnecea    Die  se 

reather  in  temperate  elixnatea  arc  gradually  being 
broken  to  pieces  by  freezing  water.  This  action  of  water 
is  called  h  7  to  distinguish  it  from  the  chemical 

..  which  we  shall  consider  presently.  The  mechani- 
cal action  of  freeting  wafc  r  cannot,  ol  course,  form  soils 

in  warm  (mm! 

Kunnmi:  wai  belpfi  to  form  soils.     Notice  the 

k  or  river  Led.  They  are  all  worn  smooth 
by  the  action  of  the  water.  Once  these  stones  wire 
rough  ind  jagged  in  shape,  but  the  running  water  has 
tumbled  them  about,  grinding  them  together  until  all 
the  rough  i  worn  olf.    The  small  particles  which 

retail  from  the  grinding  are  deposited  by  the  water  and 
go  to  form  soils. 

70.  Chemical  Action  of  Water. — Rain  water  dim 
manj  salts  bom  the  soil  and  washes  the  soil  from  ex- 
.  but  it  compensates  for  this  mischief  by 
tiding  in  the  formation  of  fresh  soil.     Bain  water  falling 
on   the  surface  of  rocks  gradually  dissolves  away  the 
ns  soluble  in  water,  and  the  insoluble  parts  crum- 
ble away  and  form  soils.    The  great  caves  in  limestone 
ru  are  the  retail  of  chemical  action  of  water.    Lime- 
is  not  very  soluble  in  ordinar  but  water 
that  has  carbon  dioxide  gas  dissolved  in  it — soda  water 
is  ordinary  water  containing  carbon  dioxide  gas — dis- 
.  much  better  than  ordinary  water.    Rain 
water  dissolves  the  carbon  dioxide  of  the  air,  and  also 
some  that  is  formed  from  the  organic  matter  in  the  soil. 


70  ELEMENTS  OF  AGRICULTURE 

This  water,  containing  carbon  dioxide,  enters  the  cracks 
and  joints  in  limestone  rocks,  and,  dissolving  portions 
of  them,  gradually  forms  larger  cracks  and  fissures 
which  in  time. grow  into  caves. 

71.  Other  Soil  Builders. — Plants  also  aid  in  the  for- 
mation of  soils.  The  fine  root  hairs  of  plants  penetrate 
the  cracks  and  crevices  of  rocks,  and  the  root  sap  dis- 
solves away  portions  of  the  rocks'  surfaces.  The  small 
plants  which  grow  on  the  surface  of  rocks,  mosses  and 
lichens,  are  especially  active  in  forming  soils.  Their 
roots  draw  all  their  mineral  food  from  the  rock,  and  so 
gradually  wear  away  the  surface. 

The  oxygen  and  carbon  dioxide  of  the  air  combine 
with  many  substances  contained  in  rocks  and,  forming 
other  compounds,  help  to  wear  away  the  original  rock. 

The  minute  bacteria  in  the  soil  also  aid  in  breaking 
up  rocks,  but  their  action  is  chiefly  on  the  organic  mat- 
ter which  all  soils  contain.. 

72.  Organic  Matter  in  Soils. — So  far  we  have  consid- 
ered only  the  mineral  matter  of  soils,  but  it  is  by  no 
means  all  of  the  soil.  A  soil  made  up  exclusively  of 
mineral  fragments  could  no  more  grow  crops  than  the 
original  rocks  from  which  the  fragments  came.  Mixed 
with  the  mineral  matter  of  soils  are  the  decaying  por- 
tions of  plants  and  animals  which  make  up  its  organic 
matter.  As  the  organic  matter  of  soil  decays  it  forms  a 
dark  substance  called  humus,  which  gives  to  many  soils 
their  dark  color.  The  organic  matter  of  soils  is  of  great 
importance,  and  we  shall  have  more  to  say  of  it. 

Soils  are  then  made  up  of  two  kinds  of  matter — or- 
ganic and  inorganic.     The  organic  matter  results  from 


HOW  SOILS  ABE  MADE  71 

the  decay  of  plants  and  animals;  the  mineral  matter 
from  the  decay  of  rocks. 

i:\ri  in \i r.ST 

When  the  tccathcr  is  sufficiently  cold,  fill  some  glass  bottle  of 
convenient  size  tcith  tcater — an  old  ink  bottle  uill  ansiccr.  Stop 
up  the  mouth  of  the  bottle  and  set  it  out  to  freeze.  By  the  ex- 
pansion of  the  water  in  freezing  the  bottle  trill  be  broken. 

Questions 

1.  What  <!<>  \\«-  mean  l>y  the  term  soil?  2.  Is  it  proper  to 
of  soil  as  dirt?  Why?  3.  To  what  part  of  the  earth's 
-nrfi..  ioM  t!i<-  word  soil  refer?  4.  What  is  the  difT 
between  a  rock  an<l  l  itoael  ">.  What  sort  of  fragments  make 
up  the  greater  pail  of  nil  loQil  •'».  How  .in-  soils  formed? 
7.  What  substnnee  i*  mod  Mttfi  in  making  soils?  8.  Describe 
the  mechanieal  action  of  water  in  forming  soils.  9.  llow  does 
the  chemieal  net  ion  of  water  help  to  form  soils?  10.  What 
other  agents  besides  pater  form  soils?  11.  From  what  sources 
do  soils  draw  their  supply  of  organic  matter? 


72 


ELEMENTS   OF  AGRICULTURE 


a 


a' 


CHAPTEE  XIV.— Classification  of  Soils 

73.  Transported  Soils. — Soils  seldom  remain  just 
where  they  are  formed,  for  the  same  forces  that  form 
them  also  move  them  about.  Water,  the  chief  soil 
former,  is  also  the  chief  soil  transporter.  Its 
action  in  moving  soils  has  been  already  men- 
tioned in  Chapter  III  under  erosion,  and 
\  may  be  better  understood  by  reference 
to  Fig.  11,  page  72.  This  figure  is  in- 
tended to  represent  a  section  of  a 
rocky  hill  or  mountain,  and  shows 
how  the  top  has  been  worn  away 
to  form  soil,  which  is  moved 
into  the  valley  below.  The 
r      dotted    line    ab 


\ 


<  a\  k' 


Fig.  11.— Erosion  of  hill  or  mountain  side.  The  soil  between  the  lines 
ah  and  a'h  has  been  washed  away,  c  shows  coarse  fragments;/,  finer 
soil ;  s,  stream. 

shows  the  original  shape  of  the  hilltop;  ab  its  present 
shape.  The  portion  between  ab  and  ab  has  been  grad- 
ually worn  away  by  frost  and  rain,  and  the  particles 
washed  by  rain  to  the  more  level  land  below.  The  coarse 
fragments  are  the  first  to  stop,  and -as  the  ground  be- 
comes more  level  the  finer  particles  are  deposited  from 


CLASSIFICATION  OP  BOOM  73 

t in-  running  water  and  form  the  fertile  mill  of  the  river 

bottom.  Many  of  the  fined  particles  are  waslu  d  into 
the  riwr  or  Greek,  inown  at  t,  and  are  carried  oh*  to  be 
rited  probably  hundred-  <»r  miles  away.  Win 
i  rises  and  Hoods  the  bottom  lands,  quantities  of 
mud  and  land  are  deposited  on  the  Hooded  area.  The 
mud  and  land  have  come  from  hillsides,  possibly  many 
miles  away,  and  in  time  they  become  part  of  the  soil  of 

the  river  bottom.  Soils  that  have  been  moved  from  the 
place  of  formation  are  called  TRANSPORTED  SOILS,  and 
are  often  a  mixture  of  soils  from  many  Localities, 

Wind  itoimi  lllO  move  soils  about  to  a  limited  extent. 
You  have  all  noticed  the  great  clouds  of  dust  blown 
about  by  high  winds;  and  in  very  dry  countries,  BUCh  as 
the    northern    portions   of   Africa,    the   amount    ol 

mored  is  considerable.    In  our  country,  with  the  exeep- 

two  Western  state-,  the  amount  o 
mored  by  winds  is  of  small  consequence 

In  some  parts  of  the  world  much  soil  has  bean  n 
and  is  ev-n  now  being  moved,  b\   gfa den,  which  are 

nothing  more  than  riven  ol  ice.    Bui  glacial  action  u  at 
lit  limited  to  I  rery  small  part  of  the  inhabited 

world,  and  need  not  concern  us. 

74.  Soils  in  Place. — Soils  that  remain  where  they  ire 
formed  are  called  SOILS  EM  P!  u  I       The  -oils  that 

the  slopes  of  hills  and  mountains  for  the  most  part 
belong  to  this  class.  Soils  in  place  are  seldom  mixed 
with  the  soils  of  other  localities,  but  result  simply  from 
the  decay  of  the  rockl  about   them. 

75.  Soils  Classified  According  to  Composition. — 8 
whether  transported  or  soils  in  place,  vary  in  the  way 


7± 


ELEMENTS    OF    AGRICULTURE 


they  are  made  up.    Different  kinds  of  rocks  when  they 
decay  make  different  kinds  of  soil.     For  convenience, 
the  various  kinds  of  soils  have  been  given  different 
names  to  indicate  how  they  are  made  up.    For  instance, 
we  have  sandy  soils,  clay  soils,  muck,  etc. 

1.  Sandy  soils  include  all  soils  that  contain  large 
amounts  of  sand.  Such  soils  are  no  doubt  familiar  to 
most  of  us. 

2.  Clay  Soils  '  include  all  those  containing  large 
amounts  of  clay.  They  may  be  easily  recognized  by 
their  sticky  character.  Soils  that  are  made  up  some- 
what equally  of  sand  and  clay  are  called  loams. 

3.  Sandy  loams  are  soils  made  up  principally  of  .-and 
and  clay,  but  containing  considerably  more  sand  than 
clay. 

1.  Clay  loams  are  also  soils  made  up  principally  of 
sand  and  day,  but  containing  more  clay  than  sand. 

5.  Soils  that  contain  much  decaying  organic  matter 
are  variously  called  humus  soils,  woods  mold,  or 
garden  soil.  If  this  variety  of  soil  also  contains 
much  moisture  it  is  called  peaty  soil,  swamp  muck, 
etc. 

These  five  classes  include  all  the  soils  commonly  cul- 
tivated on  the  farm.  There  are  other  kinds  of  soil  dif- 
ferent from  any  of  these,  but  they  are  not  the  ordinary 
farm  soils. 

76.  Light  and  Heavy  Soils. — Soils  are  often  spoken  of 
as  light  or  heavy,  but  these  words  have  no  reference 
to  the  actual  weight  of  the  soil ;  they  refer  simply  to  the 
way  these  soils  behave  when  cultivated.  A  light  soil  is 
one  that  is  easy  to  cultivate;  such  soils  are  porous,  and 


CLASSIFICATION1   <>F  SOILS  75 

the  plow  or  other  implement  of  cultivation  moves 
throu.Lrli  them  easily.  A  heavy  soil  ii  one  thai  is  more 
difficult  to  cultivate;  it  is  stiff  and  offers  triors  i 
ance  to  the  plow  of  spade  than  s  light  aoiL  The  so- 
called  light  soil,  as  a  rule,  contains  much  sand,  and  is 
by  weight  the  heaviest  of  all  soils.    The  heavy  leOi 

contain  much  clay,  which   is  lighter  than  sand.     Soils 
that  contain  much  organic  matter,  peaty  soila,  an  often 
light  in  both  0911801  of  the  word.    The  following  figures 
approximately  the  weights  of  the  different  soils: 

Dry  Sand. ...  l<><>  to  r.'<>  pounds  per  cubic  foot 

Loam 00  to  100  pounds  per  cubic  foot. 

Clay   78  to   80  pounds  per  cubic  foot 

Peat,  etc 30  to   60  pounds  per  cubic  foot 

77.  Warm  and  Cold  Soils. — According  to  their  power 

of   retaining   the  sun's   heat,  soils  are  called   \v.\KM    01 

cold.  The  amount  of  heat  absorbed  raries  greatly  in 

different  SOila,  and  depends  on  several  conditions,  hut 

may  he  to  some  SXl  ated  by  careful  .ultivat ion. 

Plants  for  their  proper  development  require  a  certain 

amount  of  heat  in  the  soil.    Bead  will  not  Sprout  until 

the  soil  has  bo  armed  to  the  required  tan 

and   DSOtt    farm  Crops  attain   their  most    Dt 
development  only  in  warm  -  art rolling,  as  far  as 

possible,  the  amount  of  heat  absorbed  by  soils  is  then 
a  matter  of  the  greatest  importance,  and  with  this  end 

in  riew  it  Is  well  to  o  tome  of  the  conditibns 

which  influence  the  amount  of  heat  in  soils. 

be  greatest  influence  on  soil  temperature; 

it  is,  in  fact,  the  great   temperature   regulator  of  the 


76  ELEMENTS    OF    AGRICULTURE 

world.  In  the  second  chapter  the  influence  of  the 
evaporation  of  surface  moisture  on  the  earth's  tempera- 
ture is  discussed.  This  action  may  be  compared  to  the 
evaporation  of  perspiration  from  the  human  body.  The 
temperature  of  the  human  body  is  prevented  from  be- 
coming too  high  by  the  evaporation  of  moisture  given 
off  through  the  skin.  So  it  is  with  the  surface  of  the 
earth,  which  may  be  called  the  skin;  when  it  becomes 
too  warm  moisture  is  given  off  and  its  evaporation  cools 
the  soil.  In  very  wet  soils  moisture  is  continually 
evaporating,  and  in  consequence  such  soils  are  usually 
cold.  In  dry  soils,  on  the  other  hand,  there  is  but  little 
evaporation,  and  the  soil  through  the  sun's  heat  be- 
comes warm.  As  a  rule,  the  dryer  the  soil  the  greater 
the  amount  of  heat  absorbed.  When  no  moisture  is 
found  the  soil  is  turned  into  a  desert. 

The  color  of  soils  also  influences  the  temperature. 
It  is  a  well-known  fact  that  dark  clothes  are  warmer 
than  white.  So  it  is  with  soils — a  dark  soil  is  warmer 
than  a  light  one-. 

The  composition  of  soils  also  has  an  effect  on  the 
amount  of  heat  absorbed.  As  a  rule,  sandy  soils  are 
warmer  than  clay  soils. 

The  fineness  of  the  soil  particles  has  also  a  marked 
influence  on  its  temperature.  Coarse,  rocky  soils  suffer 
from  extremes  of  temperature.  In  fine,  well-cultivated 
soils  the  temperature  is  almost  uniform. 

Questions 

1.  Soils  that  have  been  moved  from  their  place  of  forma- 
tion are  called  what?  2.  Soils  that  remain  where  they  are 
formed  are  called  what?  3.  By  what  means  are  soils  usually 


cla  "N  .■!  90HJ  n 

transported?  4.  Name  the  several  classes  Into  which  soils 
may  be  divided?  5.  What  is  a  sandy  soil?  6.  What  is  a 
loam?  7.  What  is  a  clay  soil?  8.  What  is  meant  by  a  light 
soil?  9.  What  is  meant  by  a  heavy  soil?  10.  What  is 
meant  by  a  warm  soil?  11.  Name  a  well  known  compound 
having  a  great  influence  on  soil  temperature?  12.  How  may 
the  presence  of  water  prevent  a  soil  from  becoming  too 
warm  ? 

PROBLEMS 

1.  If  a  soil  weighs  78  pounds  to  the  cubic  foot,  how  many 
pounds  In  an  acre  of  such  soil  one  foot  deep? 

2.  If  a  soil  weighs  90  pounds  to  the  cubic  foot  and  con- 
tains 75  per  cent  of  sand,  what  is  the  weight  of  the  sand 
in  one  acre  of  such  soil  one  foot  deep? 


73  ELEMENTS    OF    AGiUCULTUIiE 


CHAPTER   XV.— Composition  of  Soils 

78.  Water. — All  fertile  soils  contain  water,  though 
the  amount  varies  greatly  under  varying  conditions. 
The  desert  soil  contains  no  water;  the  soil  of  the  swamp 
contains  an  excess  of  water;  and  between  these  two  ex- 
tremes are  the  great  areas  of  cultivated  soils.  Water  is 
a  necessary  part  of  all  fertile  soils. 

79.  Organic  Matter. — Besides  Avater  there  are  two 
kinds,  of  matter  making  up  soils — organic  and  inorganic. 
If  a  sample  of  soil  be  gently  heated  in  an  oven  it  loses 
in  weight,  and  the  loss  is  due  to  the  evaporation  of 
moisture.  If -the  sample  be  burned  at  a  dull,  red  heat 
it  loses  niore  in  weight  and  changes  color;  this  loss  is 
due  to  the  burning  of  organic  matter,  which  passes  off 
as  gas  and  smoke  just  as  it  does  when  a  plant  is  burned. 
See  page  46. 

The  organic  matter  of  soils  results  from  the  decay  of 
plants  and  animals.  In  cultivated  fields  the  organic 
matter  comes  mainly  from  the  stubble  of  harvested 
crops,  the  decay  of  dead  weeds,  and  from  the  addition 
of  stable  manure.  In  wood  land  it  results  from  the 
decay  of  dead  leaves  and  the  fallen  branches  and  trunks 
of  trees.  As  the  organic  matter  of  plants  is  made  up  of 
C,  H,  0,  N,  S,  so  :he  organic  matter  in  the  soil  must 
be  made  up  of  the  same  elements;  and  as  organic  mat- 
ter decays  these  elements  form  compounds  which  serve 
in  time  to  build  up  other  plants.     Thus  the  organic 


rcwi  <»F  SOTTAS 


matter  of  plants  may  Df  Hied  OW  and  over  again  f«»r 
plant  food. 

Tin-  decay  <>r  rotting  of  organic  matter  in  soils  is  doe 
lo  the  action  of  bacteria  which  inhabit  1 1 1 < -  soil.  Thete 
bacteria  feed  on  the  organic  matter  and  cause  decay. 
They  are  sensitive  t<>  heat  and  cold,  and  require  a  con- 
stant supply  of  fresh  air  ami  water.  That  these  state- 
ments are  true  i>  shown  1>\    the  following  well-known 

facta:  Dead  organic  matter  does  not  decay  when  frozen; 

thm  frozen  meat  0T  Vegetables  may  he  kept  for  \var< 
ami  -how  m>  sign  Of  de.av.  Dead  «>r<ranic  matter  may 
he  dried  and  kept   for  a  long  time,  hut  when  moistened 

Dried  or  smoked  meat  is  a  good  example  of 

this.  If  sealed  np  from  the  air.  organic  matter  keeps 
indefinitely.  Canned  goods  are  an  example  of  this  fact. 
The  conditions  under  which  the  bacteria  of  decay  act 
beai  arc  the  same  a-  t'  ssary  for  the  Bpronting 

il.    They  reqnire  heat,  moistnre,  and  air.  and.  as 
in  the  case  of  the  seed,  it  i-  the  oxygen  of  the  air  that  is 

■ted. 

\-  we  hare  already  learned,  the  decay  of  the  dead 

organic  matter  of  the  soil  results  in  the  formation  of  a 

1  hiunua,  Humus  is  a  dark,  almost  bla<  k, 

product,  which  gives  to  garden  soil  its  rich,  dark  color. 

It  i-  a  mixture  of  many  different  compounds,  all  of 

which  are  made  up  of  the  four  elements — earlxtn.  hydro- 
gen, oxygen,  and  nitrogen.  Hnmus  is  of  greet  import- 
ince  in  the  soil,  and  we  shall  haw  more  to  say  of  it 
later  on. 

80.  Inorganic  Matter. — The  mineral  matter  which 
make-  up  mire  than  90  .,«  :-  .  mix- 


80 


ELEMENTS    OF    AGRICULTURE 


ture  of  many  different  compounds.  But  there  are  two 
compounds  which  are  common  to  all  soils  and  which 
serve  as  a  basis  for  their  classification.  These  two 
compounds  are  sand  and  clay. 

81.  Sand. — The  element  silicon,  when  combined  with 
oxygen,  forms  a  hard  compound,  which  we  know  as 
quartz  rock.  Quartz  often  forms  small  crystals,  and  in 
this  form  makes  up  a  large  part  of  many  kinds  of  rocks, 
such  as  granite,  sandstone,  and  some  forms  of  limestone. 
When  these  rocks  decay,  the  quartz  particles  being  very 
hard  and  insoluble,  remain  behind  and  form  what  is 
known  as  sand.  Besides  quartz  grains,  sand  contains 
fragments  of  other  minerals,  such  as  mica,  particles  of 
iron,  and  lime.  Sand  is  seldom,  if  ever,  made  up  ex- 
clusively of  quartz.  Silica,  as  quartz  is  called,  makes 
up  more  than  one-half  of  the  dry  land.  It  is  found  in 
many  rocks,  and  makes  up  a  large  part  of  most  soils.  It 
is  one  of  the  most  abundant  substances  on  earth.  Silica 
is  almost  insoluble  in  water;  the  sand  of  river  and  creek 
beds  being  practically  unaffected  by  the  running  water. 
Water  runs  through  sand  easily,  and  after  being  wet  the 
sand  dries  out  quite  rapidly.  Sand  has  no  tendency  to 
become  sticky,  and  though  wet  sand  may  stick  to  one's 
clothes  or  person,  it  is  easily  brushed  off.  Sand  absorbs 
much  of  the  sun's  heat,  as  any  one  who  has  walked 
through  warm  sand  with  his  bare  feet  can  testify.  Sand 
alone  makes  a  poor  soil  for  growing  plants ;  besides  sup- 
plying little  food  itself,  it  holds  little  or  no  moisture 
and  becomes  very  hot  when  exposed  to  the  sun. 

82.  Clay. — This  substance  in  its  properties  is  very 
different  from  sand,  though  it  is  what  chemists  call  a 


COMPOSITION  OP  SOILS  81 

silicate;  that  is,  it  contains  the  two  elements  which 
make  sand,  combined  with  another  called  aluminum. 
Aluminum  is  a  light  metal,  much  like  silver  in  appear- 
ance, and  much  used  for  manufacturing  small  articles, 
such  as  combs,  penholders,  etc.  The  metal  aluminum 
is  made  from  clay.  Aluminum,  silicon,  and  oxygen  make 

CLAY. 

Clay  Is  a  very  soft  substance,  smooth  and  almost 
greasy  to  the  touch.  When  dry  it  may  be  easily  pul- 
verized, falling  into  a  powder  as  fine  as  the  finest  flour. 
Pure  clay,  such  as  the  fine  grades  of  kaolin,  has  no 
sand  or  grit  in  it,  and  may  be  easily  cut  with  a  knife. 
When  wet  it  Incomes  sticky  like  dough  or  putty,  and 
may  be  moulded  into  any  desired  shape.  Kaolin  or  pure 
clay  is  used  to  manufacture  potter}'  and  chinaware. 

1.1  the  soil,  clay  exists  as  a  fine  powder,  and  it  is  the 
clay  particles  that  make  soil  sticky.  Clay  when  once 
wet  dries  out  slowly,  hence  (lav  -<»il>  retain  water.  As 
clay  soils  retain  much  witer,  which  evaporates  slowly, 
they  are,  as  a  rule,  cooler  than  sandy  soils.  Clay  ami 
land  have  almost  opposite  efiecti  in  a  soil.  Clay  in  soils 
holds  water,  making  the  soil  cool  and  moist.  It  is 
sticky,  a i  to  bind  the  particles  of  soil  tog« 

Sand,  on  the  other  hand,  holds  little  moisture,  and  its 
presence  tends  to  make  the  soil  warm  and  dry.  Its 
particles  are  not  sticky;  hence  sandy  soils  are  loose  and 
easy  to  work. 

i:\PKRTMENT 

Take  tome  dean  Kind,  wet  it  and  mould  it  into  any  desired  thape. 
Notice  how  toon  it  driet  out  and  crumble*  to  piece*.    Pour  water  on 
6 


o2  ELEMENTS    OF   AGRICULTURE 

dry  sand  and  notice  how  quickly  it  runs  through,  and  how  soon  the 
surface  of  the  sand  dries  out.  Treat  some  ordinary  clay  in  the  same 
way  and  notice  how  differently  it  behaves.  Mix  the  sand  and  clay 
in  varying  proportions  and  find  the  proportions  of  each  required  to 
furnish  a  mixture  resembling  the  soils  in  your  neighborhood. 

Questions 

1.  Of  what  two  kinds  of  matter  besides  water  are  soils 
made  up?  2.  The  organic  matter  in  soils  comes  from  what 
two  sources?  3.  What  elements  make  up  the  organic  mat- 
ter of  soils?  4.  What  causes  the  decay  of  organic  matter 
in  soils,  and  what  substance  is1  produced  by  this  decay? 
5..  Why  is  it  that  frozen  meat  or  vegetables  keep  so  well? 
6.  Why  is  it  that  smoked  or  dried  meats  keep?  7.  Why  is 
it  that  canned  meats  keep?  8.  From  what  source  is  the 
mineral  matter  of  soils  derived?  9.  Name  the  three  prin- 
cipal constituents  of  soil.  10.  Of  what  two  elements  is  sand 
made  up?  11.  What  are  large  rocks  made  up  of  these  two 
elements  called?  12.  How  is  sand  formed?  13.  How  does 
clay  behave  when  wet?  14.  How  would  figures  moulded 
of  wet  sand  behave  when  dry? 


COMPOSITION  OF  801L8  b'S 


CHAPTER  XVI.— Composition  of  Soils 
(Continued) 

83.  Plant  Food  in  Soils. — In  the  last  chapter  we  con- 
sidered four  substances — water,  organic  matter,  sand, 
and  clav,  which  make  up  so  large  a  part  of  all  soils.  l»ut 
while  these  substances  make  up  a  large  part  of  all  soils, 
they  furnish  the  plant  with  but  a  small  part  of  its 
mineral  matter.  Water  and  organic  matin-  ire  both 
indispensable  as  plant  foods,  but  sand  is  <>f  almost  no 
value,  and  pure  clay  is  little  better  than  sand.  Sand 
and  clay  are  not  of  much  use  as  plant  foods,  but  they 

as  a  sort  of  storehouse  for  the  plant  supply  of  food 
and  water,  and  they  also  make  up  the  soil  in  which  the 
plant  roots  grow  and  develop.  The  clay  particles  in  the 
soil  hold  water  from  which  the  plant  may  draw  its  sup- 
ply. They  also  hold  certain  valuable  plant  foods  which 
they  give  up  to  growing  plants.  Sand  prevents  the  soil 
from  becoming  too  wet  and  sticky,  and  also  ah 
much  heat  from  the  sun.  Mixed  in  with  the  sand,  clay, 
and  organic  matter  are  small  quantities  of  various  min- 
eral compounds  that  make  up  the  ashes  of  plants.  Four 
mineral  elements  are  absolutely  necessary  to  the  growth 
of  plants;  they  are  phosphorus,  potassium,  calcium,  and 
iron.  Many  others  are  found  in  the  ash  of  plants,  hut 
thrv  do  not  seem  to  be  as  necessary  as  the  four  men- 
tioned. 

84.  Phosphorus  in  Soils. — This  element  in  some  form 


84  ELEMENTS    OF   AGRICULTURE 

of  combination  is  found  in  all  soils,  and  comes  from  the 
decay  of  rocks  which  contain  phosphorus  compounds. 
It  is  in  some  instances  found  combined  with  lime,  in 
which  form  it  is  called  bone  phosphate,  making  up, 
as  it  does,  a  large  part  of  the  bones  of  all  animals. 
Often  it  is  found  combined  with  iron  and  aluminum, 
when  it  is  called  iron  and  aluminum  phosphate. 
Most  soils  contain  comparatively  small  quantities  of 
phosphates,  .1  per  cent,  being  a  fair  supply;  some  rich 
soils  may  contain  as  much  as  .5  per  cent,  but  this  is 
unusual.  Poor  soils  contain  not  more-  than  .05  per 
cent.  Besides  the  phosphates  mixed  with  the  finer 
soil  particles,  many  of  the  coarse  fragments  in  the 
soil  contain  a  small  quantity  of  phosphates,  which,  as 
the  fragments  decay,  is  added  to  the  fine  soil. 

85.  Potassium  in  Soils. — Compounds  of  this  element 
are  found  in  all  soils,  and  come  from  the  decay  of  rocks 
containing  potash.  The  rocks  which  supply  most  of 
the  potash  of  soils  are  called  feldspars,  and  are 
found  all  over  the  earth.  The  potash  in  the  soil  is 
usually  combined  with  silica  lo  form  compounds 
known  as  potassium  silicates. 

Clay  comes  largely  from  the  decay  of  the  same  rocks 
that  supply  potash  to  the  soil,  and  as  clay  is  also  a 
silicate  it  is  often  united  with  potash  to  form  double 
silicates.  The  amount  of  potash  in  different  soils, 
of  course,  varies  greatly;  in  some  soils  it  reaches  as 
high  as  2  per  cent;  in  poor  soils  it  often  falls  below  .1 
per  cent. 

86.  Calcium  in  Soils. — Compounds  of  this  element 
make  up  a  small  part  of  all  fertile  soils,  and  are  the 


'COMPOSITION  OP  80IL8  85 

result  of  the  decay  of  rocks  containing  some  form  of 
calcium.  The  compounds  of  calcium  found  in  soils 
are  popularly  called  LIME.  In  regions  where  limestone 
rocks  are  abundant  the  ^>il  is  well  supplied  with  lime; 
but  where  the  soil  has  been  formed  by  the  decay  of 
BUCh  nxks  as  sandstone  but  little  lime  will  be  found. 
The  amount  of  lime  in  the  soils  is,  ol*  course,  depend- 
ent on  the  amount  of  lime  in  the  rocks  from  which 
ire  formed,  and  for  this  reason  the  supply  of  lime 
in  \arious  soils  is  very  different  As  already  men- 
tioned, the  soils  of  limestone  regions  are  well  supplied, 
and  are,  as  a  rule,  very  fertile.  The  soils  of  the  fa- 
mous bluegrass  regions  of  Virginia,  Tennessee,  and 
Kentucky  are  formed  from  limestone  rocks,  and  are 
noted  for  their  fertility.  Besides  forming  plant  food, 
lime  has  a  decided  influence  on  the  supply  of  nitrogen 
in  the  soils  and  also  on  their  mechanical  condition. 

quantity  of  lime  in  soils  varies  greatly;  in 
rich  limestone  soils  it  may  reach  2  to  3  per  cent,  and 
in  poor,  sandy  soils  fall  as  low  as  .1  per  cent.  The 
calcium  in  soils  is  usually  combined  with  carbon  and 
oxygen  to  form  a  carbonate,  or  with  phosphorus  and 
oxygen  to  form  phosphates.  Sometimes  it  is  cont- 
inued with  ralphur  and  oxygen  to  form  a  sulphate. 

87.  Iron  in  Soils. — This  element  occurs  abundantly 
in  all  soils,  however  poor.  It  is  usually  found  com- 
hmed  with  oxygen,  forming  an  oxide,  or  with  oxygen 
and  water  to  form  a  hydrate;  at  times  it  is  combined 
with  phosphorus  and  aluminum.  Nearly  all  rocks  con- 
tain iron,  whieh  Womes  a  part  of  the  soil  when  the 
rocks  decay.     Iron  gives  to  soils  their  various  colors 


86  ELEMENTS    OF    AGRICULTURE 

of  red  or  yellow.  The  amount  of  iron  in  most  culti- 
vated soils  seldom  falls  below  1  per  cent. 

88.  Other  Elements  in  Soils. — Sodium,  magnesium, 
chlorine,  aluminum,  and  a  number  of  other  elements 
besides  those  already  mentioned  are  found  in  soils; 
but  they  are  of  little  importance  as  plant  foods,  so  need 
only  be  mentioned. 

89.  Analyses  of  Soils. — To  analyze  a  soil  means  to 
determine  the  various  elements  and  compounds  it  con- 
tains. The  following  figures  show  the  comparative 
composition  of  samples  of  rich  and  poor  soils.  These 
figures  are  from  actual  analyses,  the  rich  loam  being  a 
sample  of  soil  from  a  rich  bluegrass  region,  and  the 
poor  sand  a  soil  from  a  very  poor  region  of  country: 

Rich  Loam.  Poor  Sand. 

Limestone  Soil.  Sandstone  Soil. 

Organic  matter 5  per  cent.  2  per  cent. 

Sand   ." 75  per  cent.  90  per  cent. 

Clay  20  per  cent.  8  per  cent. 

With  the  sand  and  clay:  ' 

Potash    0.5  per  cent.  0.1    per  cent. 

Phosphoric  acid 0.2  per  cent.  0.05  per  cent. 

Lime    0.5  per  cent.  0.05  per  cent. 

Iron    2.    per  cent.  0.8    per  cent. 

Questions 

1.  How    do   sand    and   clay   aid    the    growth  of   plants? 

2.  Name  four  mineral  elements  necessary  to  plant  growth. 

3.  From  what  does  the  phosphorus  in  soil  come?  4.  With 
what  other  compounds  is  it  usually  combined?  5.  Give 
some  idea  of  the  amount  of  phosphoric  acid  found  in  soils. 

6.  From  what  rocks  does  the  soil's  supply  of  potash  come? 

7.  With  what  substance  is  the  potash  of  soils  usually  com- 
bined?   8.  What  rocks  form  soils  rich  in  lime?   9.  Why  do 


00MPOSITH».\  (IF  SOILS 


B7 


sandstone  soils  contain  little  lime?  10.  What  is  a  general 
characteristic  of  limestone  soils?  11.  With  what  element 
is  the  calcium  in  soils  usually  combined? 

PROBLEMS 

'  1.  A  sandy  soil  weighs  110  pounds  to  the  cubic  foot,  and 
contains  0.04  per  cent  of  lime.  Calculate  the  total  weight 
of  lime  in  an  acre  of  such  soil  one  foot  deep. 

2.  A  rich  loamy  soil  weighs  90  pounds  to  the  cubic  foot 
and  contains  0.60  per  cent  of  lime.  Calculate  the  weight 
of  lime  in  an  acre  of  auch  soil  one  foot  deep. 


88  ELEMENTS    OF   AGRICULTURE 


CHAPTER  XVII.— Water  in  Soils. 

90.  Importance  of  Water  in  Soils. — Water  and 
nitrogen  have  both  been  mentioned  as  making  np  a  part 
of  all  fertile  soils,  but  so  far  we  have  devoted  little  space 
to  them.  These  two  plant  foods  are  of  so  much  impor- 
tance that  they  each  require  a  separate  chapter  for  their 
consideration,  and  we  shall  begin  with  water.  In  order 
that  any  soil  may  grow  plants  a  supply  of  water  is 
absolutely  necessary;  therefore  it  is  of  the  first  im- 
portance. 

91.  Film  Moisture. — Soils  are  made  up  of  a  great 
number  of  particles  of  various  shapes  and  sizes  piled 
loosely  together.  A  pile  of  broken  rocks  or  stones  may 
serve  to  illustrate  on  a  large  scale  how  soils  are  made 
up.  The  spaces  between  the  soil  particles  are  filled  with 
air  or  water,  as  the  case  may  be.  In  dry  soils  most  of 
the  spaces  are  filled  with  air;  but  when  the  soil  becomes 
wet  the  air  is  driven  out,  and  they  become  filled  with 
water,  and  at  the  same  time  each  soil  particle  becomes 
surrounded  with  a  film  of  water.  Dip  a  marble  in 
water  and  notice  how  it  comes  out  wet  all  over;  it  is 
surrounded  by  a  layer  or  film  of  water.  When  soil 
becomes  thoroughly  wet  each  soil  particle  is  surrounded 
by  a  film  of  moisture,  like  the  wet  marble.  The  water 
filling  the  air  spaces  soon  sinks  deep  into  the  soil 
and  part  of  it  drains  off,  leaving  in  the  upper  soil  only 
the  moisture  surrounding  each  particle  of  soil,  or  what 


WATKl: 


89 


is  called  the  film  moisture.  This  does  not  drain  off 
and  serves  to  keep  the  soil  moist,  supplying  water  for 
growing  plants.  The  amount  of  water  held  as  film 
moisture  varies  greatly  in  different  soils. 

Pour  water  over  a  pile  of  broken  stones  or  coarse 
gravel.  Each  stone  soon  becomes  surrounded  by  a  film 
of  water;  then  the  pile  will  hold  no  more  water,  and  if 
more  is  added  it  simply  runs  off.  Exposed  to  the  air 
or  sun,  the  pile  of  stones  soon  dries  out,  and  the 
moisture  disappears,  leaving  the  stones  as  dry  as  before 
they  were  wet  Now,  pour  water  on  a  lump  or  two  of 
dry  clay,  of  about  the  same  weight  as  the  stones,  and 
notice  bow  much  more  water  it  absorbs  than  the  stones. 
the  day  becomes  thoroughly  wet,  it  may  be 
exposed  to  the  air  and  sun  a  long  time  before  it  dries 
out.  The  <lav  consists  of  a  greai  number  of  small 
particles,  each  of  which,  when  wet,  becomes  co 
with  water;  mod  of  the  air  spaces  between  the  particles 
are  also  tilled,  and  in  this  way  much  water  U  taken  up. 
As  only  the  outer  particles  are  exposed  to  the  air  and 
sun  the  tump  dries  out  slowly.  The  pile  of  stones,  on 
the  other  li/md,  consists  of  a  small  number  of  coarse 
particles,  and  consequently  liolds  less  film  moisture. 
Thr  water  qnickly  drains  from  the  air  spaces,  tearing 
each  particle  exposed  to  the  air,  which  quickly  evapo- 
i  the  film  moisture, 

The  Cornell  Experiment  Station  has  published  two 
interesting  drawings  illustrating  the  amount  of  water 
held  by  different  soils.     This  experiment  was  ma 
the  Station  Chemist,  and  is  described  as  follows: 

*  lie  put  small  marbles  in  s  tumbler,  as  shown  by 


90 


ELEMENTS    OF    AGRICULTURE 


SEJ1K*. 


Fig.  12,  and  the  total  amount  of  film  moisture  that  the 
marbles  would  carry  is  represented  in  the  tube  placed 
beside  the  tumbler.  The  soil  in  the  other 
tumbler  (Fig.  13)  is  of  the  same  weight  as 
the  marbles  in  Fig.  12,  and  it  represents  the 
marbles  reduced  to  the  fineness  of  common 
sand.  Its  capacity  for  holding  film  moisture 
is  represented  by  the  water  in  the  standing 
tube  (Fig.  13).  The  weight  of  material  is 
the  same  in  each  tumbler,  and  the  reason 
why  one  holds  three  times  more  film  moist- 
ure than  the  other  is  due  to  the  increase  of 
surface  that  comes  by  dividing  a  coarse  lump 
into  fine  particles."* 

This  experiment  seems  to  prove  conclu- 
sively that  the  power  of  a  soil  to  hold  water 
depends  in  a  large  measure  upon  the  fine- 
ness of  its  particles. 
92.    Free    Water.— 

When  rain  falls  on  the 

surface    of   the    earth, 

part   of   it   sinks   into 

the  soil  until  it  reaches 

some    hard    layer     of 

earth  or  rock,  through 


-  Fig.    12  —Film 

moisture     held    by  xrViiph 

marbles.  (From  w"1^11 

Bulleiin     No.     174,  rpy.^ 

Cornell     Experi-  Xllfc; 
ment  Station.) 


Fig.    1 8.— F  i  1  m 

moisture    held    by 

if    r.onnrk+    noce    marbles    when    re- 

lt   cannot  pass.  duced   t0  poWder. 

,i     ±.      u«„   (From  Bulletin  No. 
Water     that     lias  174  Cornell  Experi- 
,      .       -.        n  p  ment  Station.) 

drained     down     trom 


the  soil  above  rests  on  this  layer,  and  follows  it  until  it 
comes  out  as  a  spring  or  well.     Fig.   14  shows  how 


♦Cornell  Experiment  Station  Bulletin,  No.  174. 


WATER  IN   Soil >  91 

i  ;md  irelli  ere  formed    The  water  thai  follows 

this  impervious  layer  u  called  I  ki  i.  or  GBi  H  m»  W  \  i  ik. 
itmguiah  it  from* the  film  moisture  surrounding 
etpfa  soil  particle.  It  nm>t  not  be  supposed  that  the 
ground  water  flows  in  a  regular  stream  along  this 
impeffioiU  stratum,  for  it  does  not.  It  fills  all  the 
spaces  in  the  soil  lying  directly  above  the  stratum,  and 
drains  gradually  towards  the  spring  (Fig,  ID.  We 
here,  then,  as  shown  in  the  figure,  Brat,  i  layer  o 
containing  only  film  moisture,  then  i  layer  ««f  wet  wil, 
containing    free    or    ground    water,    and,    finally,    the 


Fio.  H.— WatiT  table  in  soil.    <i  b.  surface  of  grounl 
•oil  containing  film  moisture;   /),  soil  containing  free 
water;  K,  impervious  stratum;  >',  spring;  A',  stream;    W% 
well .    x  s,  line  of  water  table. 

impervious  layer.  The  digging  of  a  well  proves  the 
truth  of  these  statements;  the  well  first  passes  through 
a  comparatively  dry  soil  which  camel  only  film 
moisture.  Finally,  the  well  reaches  a  layer  of  soil 
which  is  wet,  and  as  it  sinks  into  this  layer  it  fills  with 
water  to  the  point  where  the  wet  soil  begins.    If  carried 

enough,  below  this  wet  soil  will  be  found  i 
of  hard  clay  or  stone.    There  is  usually  a  well  marked 
line  when  the  soil  containing- film  moisture  ends  and 

the   free  water  begins;  the  line  x  tj  z  in   Rg.   14  shows 

where  the  change  occurs,  and  it  is  called  the  water 


92  ELEMENTS   OF  AGStCtMtJftE 

table.  The  water  table  is  the  beginning  of  the  free 
water  in  the  soil.  Below  the  water  table  the  soil  is  like 
a  great  sponge  filled  with  water,  and  it  is  from  this 
supply  of  free  water  that  the  soil  above  draws  its  supply 
in  dry  weather.  The  bottom  of  wells  must  always  go 
below  the  water  table.  As  film  moisture  evaporates 
from  the  surface  soil,  more  rises  from  the  free  water 
below  to  take  its  place.  Dip  the  end  of  a  dry  towel  in 
water,  and  notice  how  the  water  rises  through  the  towel 
towards  the  dry  end;  a  dry  sponge  sucks  up  water  in 
the  same  way  and  illustrates  perfectly  how  film  water 
rises  towards  the  surface  of  the  soil.  Part  of  the  free 
water  drains  from  the  soil  at  some  spring  or  well,  and 
the  remainder  rises  to  supply  the  film  moisture  in  the 
soil  above.  The  supply  of  water  in  soils  is  renewed 
from  time  to  time  by  rain,  and  as  more  rain  falls-the 
water  table  rises;  in  very  wet  weather  it  may  reach  the 
surface  of  the  ground,  and  when  such  is  the  case  the 
soil  is  completely  saturated  with  water.  In  dry  weather 
as  the  water  drains  from  the  soil,  the  water  table  sinks 
lower  and  lower,  till  finally  it  sinks  so  low  that  almost 
no  film  moisture  reaches  the  soil  above.  Then  a 
drought  is  at  hand,  and  plants  growing  in  the  soil 
suffer  for  water. 

93.  Deep  and  Shallow  Soils. — When  the  impervious 
stratum  is  near  the  surface  of  the  soil  the  water  table 
is  also  near  the  surface,  and  consequently  in  rainy 
weather  the  soil  becomes  very  wet;  on  the  other  hand, 
in  dry  weather  the  small  quantity  of  film  moisture  in 
the  soil  evaporates  quickly,  and  leaves  the  soil  very  dry. 
Such  soils  are  said  to  be  shallow.     When  the  imper- 


WA1  KB    IN     SOILS 


93 


13 
m? 

I* 
11 

|5 

&! 

is 
is 

3» 


vious  stratum  is  far  below  the  surface  the  soil  is  said 
to  l»e  deep. 

then,  is  found  in  the  soil  in  two  forms;  in 
the  soil  near  the  surface  it  ordinarily  exists  as  film 
moisture.  In  the  lower  soil  it  ii  found  as  free  water, 
which,  rising  in  the  soil,  forms  the  film 
moisture  abort. 

EXPERIMENT 

To  illustrate  how  free  water  rises  in  soil  and  becomes 
Aim  moisture,  the  following  simple  experiment  is  useful: 

Take  an  ordinary  glass  tube  of  any  convenient  size 
and  stop  up  one  end  with  a  plug  of  loosely  fitting  cotton. 
Then  fill  the  tube  with  dry  soil.  Dip  the  end  with  the 
cotton  plug  in  water  just  deep  enough  to  cover  the  end 
of  the  tube.  Water  rises  through  the  dry  soil  until  it  is 
all  thoroughly  moistened.  Fig.  15  illustrates  this  ex- 
periment. 

Questions 

1.  When  a  marble  is  dipped  into  water  what 
happens  to  it?  2.  When  water  is  poured  on  a 
pile  of  stones  with  what  does  each  stone  become 
surrounded?  3.  When  rain  water  soaks  into 
the  soil  with  what  is  each  little  soil  particle 
surrounded?  4.  What  is  the  moisture  surrounding  each 
soil  particle  called?  5.  Which  absorbs  the  more  moisture, 
a  pile  of  fine  earth  or  a  pile  of  stones,  and  which  dries  out 
the  more  rapidly?  6.  When  water  which  soaks  through  the 
soil  reaches  a  hard  layer  of  soil  or  rock  through  which  it 
cannot  pass  what  happens  to  it?  7.  What  is  the  water  that 
fills  the  soil  Just  above  the  impervious  stratum  called? 
8.  The  dividing  line  between  the  soil  filled  with  free  water 
and  that  containing  film  moisture  is  called  what?  9.  Why 
does  the  level  of  a  water  table  change?  10.  How  deep  does 
a  well  have  to  go  In  the  soil  before  It  reaches  water? 
ll  How  does  the  free  water  supply  film  moisture  to  the 
soil  above?  12.  In  wet  weather  how  does  the  water  table 
behave 7 


94  ELEMENTS    OF   AGRICULTURE 


CHAPTER  XVIIL— Nitrogen  in  Soils 

94.  Importance  of  Nitrogen  in  Soils. — -We  have 
already  mentioned  the  fact  that  nitrogen  is  one  of  the 
most  important  of  all  plant  foods.  It  is  important 
because  no  plant  can  grow  without  a  supply  of  this 
element,  and,  furthermore,  because  the  supply  in  the 
soil  is  easily  exhausted  through  careless  cultivation, 
and,  when  once  exhausted,  is  with  difficulty  replaced. 
It  seems  strange  that  plants  should  ever  want  for 
nitrogen  when  they  are  surrounded  by  air  which  is  four- 
fifths  nitrogen.  But  there  are  only  a  few  kinds  of 
plants  that  can  make  any  use  of  the  nitrogen  of  the 
air,  and  even  for  them  the  nitrogen  must  first  enter  the 
soil  and  there  be  changed  into  the  proper  compounds. 
All  of  the  plant's  nitrogen  supply  is  taken  in  through 
its  roots. 

95.  Sources  of  the  Soil's  Supply  of  Nitrogen. — The 
soil's  supply  of  nitrogen  comes  from  three  sources. 
First,  and  most  important,  is  the  nitrogen  combined 
in  the  organic  matter  in  the  soil;  second,  the  nitro- 
gen contained  in  the  air  which  fills  many  of  the  spaces 
between  the  soil  particles;  third,  the  compounds  of 
nitrogen,  ammonia  and  nitrates,  which  are  washed 
from  the  air  by  rain  water.  The  amount  of  nitrogen 
brought  to  the  soil  by  rain  water  is  insignificant  com- 
pared with  the  amount  supplied  by  organic  matter. 
The  nitrogen  held  by  the  air  in  the  soil  is  useful  to 
only  certain  kinds  of  plants,  and  by  far  the  most  im- 


NITROOKN    Df    SOILS 


95 


portant  compound-  of  nitrogen  are  those  contained  in 
the  organic  matter. 

96.  Nitrification. — All  the  nitrogen  compounds  of 
plants  ;ire,  as  stated  before,  called  by  one  name — 
protein.  When  plants  decay  in  the  soil  the  protein 
compounds  are  destroyed  by  the  bacteria  which  feed 
on  the  organic  matter.     Most   of  the  nitrogen  of  the 

in  compounds  is  finally  changed  by  the  processes 
of  decay  into  other  compound-  of  nitrogen,  which  are 
known  ei  nitrates,  and  this  change  is  called  nitrifi- 

>\\ 
All  (  f  the  changes  which  the  protein  compounds 
undergo  in  being  converted  into  nitrates  are  caused 
by  bacterial  which  work  only  under  certain  conditions. 
These  condition-  have  already  been  Mated  on  page  78, 
and  they  show  that  in  temperate  regions  of  the  i 
nitrification  can  only  take  place  during  the  summer 
months.  This  is  fortunate,  for  the  nitrogen  compounds 
formed  by  this  process  arc  very  easily  dissolved   in 

.  and  if  not  taken  up  by  growing  plants  would  be 
quickly  washed  from  the  soil  by  rain  water  and  so  lost. 
Nitrification  can  only  take  place  in  moist  soils  well 
supplied  with  air,  and  is  mod  active  when  the  tem- 
perature is  between  95°  and  100°  K.  Nitrification 
when  the  temperature  rises  above  130°  F.  or 
falls  below  53°  F.    The  nitrates  are  easily  dissolved  in 

.   and   in   this  condition   pass  into  the  roo; 
plants  and  are  finally  built   dp  by  the  growing  plant 
into    fresh    protein    compounds.     By   this   process  of 
nitrification  the  same  nitrogen  is  o 
again.     But,  of  course,  there  is  always  some  loss  of 


96 


ELEMENTS    OE   AGRlCtTLTr/RE 


nitrogen.     During  the  process  of  decay  some  of  the 

• 

nitrogen  escapes  into  the  air  in  the  form  of  ammonia; 
the  smell  of  ammonia  may  often  be  noticed  rising  from 
decaying  organic  matter.  Then  some  of  the  nitrates 
are  washed  from  the  soil  by  rain  water.  In  some  way 
this  loss  must  be  made  good,  else  the  store  of  nitro- 
gen in  time  becomes  exhausted.  The  nitrogen  com- 
pounds washed  from  the  air  are  not  in  sufficient 
quantity  to  make  good  this  loss,  the  minerals  in  the 
soil  can  supply  no  nitrogen,  and  the  only  remaining 
source  is  the-  free  nitrogen  of  the  air. 

It  is  only  within  the  last  few  years  that  we  have 
learned  that  some  plants  make  use  of  the  nitrogen  of 
the  air  for  food.  Beans,  peas,  clover  and  other  plants 
of  the  botanical  famity  which  is  known  as  the 
leguminos^e  or  pulse  family,  all  contain  notably 
large  quantities  of  protein.  Yet  these  crops  often 
grow  and  flourish  on  soils  which  will  not  produce 
crops  of  wheat,  corn,  or  oats  until  some  nitrogeneous 
fertilizer  is  added.  That  the  plants  of  the  leguminous 
family  could  draw  on  some  supply  of  nitrogen  which 
was  not  available  to  other  crops  has  been  a  recognized 
fact  for  many  years.  But  how  or  where  they  got  their 
nitrogen  was  not  known  until  recently.  Now,  we 
know  that  leguminous  plants  obtain  parts  of  their 
nitrogen  from  the  air,  and  that  it  is  supplied  to  them 
by  bacteria.  On  the  roots  of  clover,  beans,  peas,  and 
other  plants  of  this  family  are  found,  ordinarily,  small 
enlargements  or  knots  which  are  called  tubercles. 
These  tubercles  are  the  homes  of  the  bacteria  which 
make  the  nitrogen  compounds  from  the  nitrogen  of 


Mil:-. «.l  V    IN    SOILS 


97 


the  air.  Tiny  li\  themeelvee  on  the  roots,  and  cause 
ill.-  taberclef  to  grow.  This  has  been  proven  by  grow- 
ing clover  or  beans  in  soil  known  to  be  free  from  all 
:ia.  When  this  was  done  no  tubercles  were 
fonned  on  the  root*,  and  the  plant-  made  i  rerj  poor 
growth.  Fig,  W  Bhowi  the  tuberclee  formed  on  the 
roots  of  a  soy  ox  Boja  bean  plant,  which  belongs  to  the 
pnlfe  faniilv.  The  bacteria  which  inhabit  the  roots  of 
leguminonfl  plant-  have  the 
powei  "I"  changing  the  free 
nitrogen  of  the  air  into  the 
compounds  of  Ditrogen  known 
;i-  nitrates — and  these  com- 
pounds are  readily  taken  op 
by  the  plant  roots.  In  this 
way,  at  it  were,  the  bacteria 
pay  rent  to  the  plant  for  th.-ir 
homea  on  it-  roota  Why  it 
is  that  theae  nitrifying  bac- 
teria live  only  on  the  r<>< 
one  family  of  plants  is  not 
known,  but  they  evidently  prefer  these  plants,  for  so 
far  as  we  know  at  present  they  do  not  inhabit  the 
roots  of  any  other  family.  The  family  «>f  leguminous 
plants  is  a  large  one.  and  BOrOfl  of  those  plant!  are  found 
in  all  soils  and  climates.  In  this  way  nature  renews 
the  -tore  of  nitrogen  in  the  soil,  hut  in  cultivated  fields 

the  condition!  are  rerj  different 

iv  soils  do  not  contain  any  of  the  bacteria  which 
change  the  nitrogen  of  the  air  into  nitrates.  In  Mich 
soils  no  tubercles  form  on  the  roots  of  legumes,  which 

7 


Fio.  10.— Roots  of  yellow 
soy  bean,  grown  at  the  Kan- 
»u  Agricultural  Kxpertment 
MAtlnn  in  IWM.on  land  inoc- 
ulated with  an  extra*' 
Lalnlngthe  tuU'rH«>-f<»rining 
bacteria.  (From  Yearbook. 
U.  8.  Dept.  Agr  ,  1897.) 


98 


ELEMENTS    OF    AGRICULTURE 


plants  are  in  consequence  forced  to  draw  their  sup- 
plies of  nitrogen  from  the  soil,  like  wheat,  oats,  or 
any  crop  having  no  power  to  use  the  nitrogen  of  the 
air.  Without  the  proper  kind  of  bacteria  legumes  are 
unable  to  make  any  use  of  the  nitrogen  of  the  air. 
To  supply  deficient  soils,  these  bacteria  are  now  pre- 
pared for  sale,  and  they  may  also  be  supplied  by  adding 
to  the  deficient  soils  quantities  of  another  soil  known 
to  contain  them.  It  is  probable  that  in  a  few  years  the 
various  nitrifying  bacteria  will  be  sold  in  the  market 
much  as  fertilizers  are  sold  to-day. 

97.  Forms  of  Nitrogen  in  Soils. — We  have  learned 
the  sources  from  which  the  soil  is  supplied  with  nitro- 
gen; now,  how  are  these  compounds  held  in  the  soil? 
A  part  of  the  nitrogen  is  held  in  the  undecayed  organic 
matter,  some  is  combined  in  the  humus,  and  the  air  in 
the  soil  contains  free  nitrogen.  In  all  of  these  forms 
the  nitrogen  is  unavailable  to  plants  for  food,  and 
must  first  be  converted  into  nitrates  by  the  bacteria 
before  it  may  be  used.  The  soil  contains  some  nitrates, 
as  does  the  soil  water,  but  these  compounds  are  in 
small  quantities  because  they  are  so  easily  washed  from 
the  soil. 

Questions 

1.  Why  is  nitrogen  particularly  important  as  a  plant 
food?  2.  From  what  three  sources  is  the  soil's  supply  of 
nitrogen  derived?  3.  What  happens  to  the  protein  com- 
pounds when  the  plant  decays  in  the  soil?  4.  What  causes 
the  decay  of  plants  in  the  soil?  5.  What  nitrogen  com- 
pounds are  formed  when  plants  decay  in  the  soil?  6.  What 
is  the  process  of  the  formation  of  nitrates  called?  7.  When 
is  nitrification  most  active?    8.  When  plants  decay  is  there 


Mli;«»<.l  I    IX    SOIL8  9V 

ever  any  loss  of  nitrogen?  9.  Name  a  family  of  plants  con- 
taining large  amounts  of  protein.  10.  Have  leguminous 
plants  the  power  of  obtaining  nitrogen  from  any  other 
source  than  the  soil?  11.  How  do  leguminous  plants  obtain 
nitrogen  from  the  air? 


100  ELEMENTS    OF    AGRICULTURE 


CHAPTER  XIX.— How  Soils  Lose  Water 

98.  How  Soils  Become  Poor.— The  fact  that  culti- 
vated soils  lose  their  fertility,  becoming  poor  and  pro- 
ducing small  crops,  is  only  too  well  known.  But  how 
this  loss  of  fertility  occurs  is  not  so  well  known,  and 
the  answer  is  not  easy  to  find. 

Growing  plants  are  very  particular  about  their  food. 
They  require  a  number  of  different  compounds,  which 
must  be  supplied  them  in  certain  combinations,  else 
the  plant  will  have  none  of  them.  If  the  soil  should 
fail  to  supply  the  plant  with  only  one  of  the  many 
foods  it  requires,  the  plant  starves,  or  if  the  food  be 
supplied  in  a  form  not  acceptable  to  the  plant,  it  will 
not  take  it.  For  •  instance,  a  soil  that  contains  no 
nitrogen,  even  though  it  contains  every  other  plant 
food,  cannot  grow  crops.  A  soil  that  contains  only 
nitrogen  combined  in  organic  matter  and  provided 
with  no  means  of  forming  nitrates  will  be  as  barren 
as  a  desert.  Fertile  soils  are  soils  that  supply  all  kinds 
of  plant  foods  and  supply  them  in  the  form  most 
acceptable  to  plants.  When  the  supply  of  any  one  or 
more  of  the  foods  becomes,  from  any  cause,  exhausted, 
the  soil  is  called  poor  or  worn,  which  means  that  it 
cannot  feed  growing  plants.  The  supply  of  plant  food 
in  most  soils  is  rarely  excessive,  and  is  often  small. 
It  is  an  easy  matter  to  exhaust,  by  improper  methods 


HoW    soils    LOS]     \V.\  :  101 

of  cultivation,  one  or  more  oi  the  different  foods,  but 

■  ■:. ■  -upply  is  not  so  easy.  The  two  plant  i 
most  easilj  exhausted  and  most  difficult  to  replace  are 
water  and  nitrogen,  and  ai  tlu-y  arc  to  a  certain  extent 
dependent  on  each  other,  l  toll  lacking  in  one  is  apt 
to  be  lacking  in  both. 

99.  Moisture   Often  Lacking  in  Soils. — The    plant 
food  moat  often  lacking  is  soils  ii  moisture.  The  great 

of  land  known  as  deserts  arc  d<  iQM  they 

baw€  no  supply  of  water.     The  oases  of  deserts  owe 

I oriatence  to  a  supply  of  water  from  some  spring 

or  well.     Provide  l  desert  with  a  supply  of  water,  and 

to  be  a  desert,  and  in  time  may  become  fertile. 

In  many  parts  of  our  country  are  great  stretch 

land,  whieli.  while  not    reduced   to  the  condition  of  a 

.  are  so  poor  that  the  crops  produced  are  hardly 
worth  the  gathering.    These  lands  were  once  clothed 

with  a  dense  growth  <>f  magnificent  forest  trees;  now 
they   produce  for  those  who  cultivate  them   the   mo>t 

mesgi  What  has  caused  the  change?     Has 

the  mineral  food  of  the  soil  become  exhausted?     Has 

the  DitrOgen  supply  been  used  up,  or  has  the  Wiit.r 
supply  failed?  If  left  uncultivated  these  lands  grow 
up   again    in    trees,    and    as    time    passes    they    become 

clothed  sgain  in  great  forests,  Bridentlj  then-  is 
enough  plant  food  accumulated  t<»  produce  great  crops 

of  trees;  then  why  not  enough  for  farm  CTOpe?  There 
b  an  ample  ttore  of  mineral  plant   food  in  these  poor 

soils,  but  two  thing!  ere  lacking    water  and  or 
matter.     Hut   if  they  arc  lacking  how  can  great  crops 
of  trees  grow  up?     Growing  trees  add  to  the  soil's 


102  ELEMENTS    OF   AGRICULTURE 

supply  of  both  water  and  organic  matter,  and  so  in- 
crease its  fertility.  How  they  do  this  is  explained  in 
succeeding  paragraphs. 

100.  How  the  Water  Supply  of  Soils  is  Renewed. — 
The  supply  of  water  in  soils  is  renewed  from  time  to 
time  by  rains,  much  of  the  rain  water  being  held  in 
the  deep  soil  as  free  or  ground  water.  From  the  deep 
soil  it  rises  into  the  surface  soil  as  film  moisture  which 
provides  growing  plants  with  a  constant  supply ._  The 
more  free  water  a  soil  holds  the  greater  the  store  for 
growing  plants.  If  for  any  reason  the  free  water  of  a 
soil  becomes  exhausted  the  plants  growing  in  the  soil 
wilt  and  die.  Growing  plants  require  a  constant  supply 
of  water,  which  they  can  obtain  only  from  the  film 
moisture  of  the  soil.  Eains  are  often  weeks  apart,  and 
unless  water  is  held  by  the  soil  plants  suffer.  The  soil 
below  the  water  table  may  be  considered  as  a  reservoir 
which  holds  rain  water,  much  as  a  sponge,  and  sup- 
plies it  as  needed  to  growing  plants.  If  there  be  a 
leak  in  the  reservoir  the  water  supply  is  lost.  The 
depth  of  the  soil  and  the  number  and  size  of  the 
soil  particles  in  a  'measure  determine  the  amount  of 
film  moisture  a  soil  is  capable  of  holding.  But  in 
order  that  a  soil  may  contain  film  moisture  water  must 
be  first  absorbed  and  held  below  as  free  water.  If  rain 
water  runs  off  the  surface,  the  soil  can  contain  but 
little  moisture.  In  bare  fields  this  is  often  the  case; 
the  rain  water  runs  off  the  surface,  cutting  great  gullies 
and  doing  much  damage  to  the  land.  On  land  covered 
with  growing  plants  or  the  litter  of  dead  plants,  rain 
water  is  prevented  from  running  off,  and  gradually 


HOW  801 L8  L08E  WAT  I  I  103 

goaks  into  the  soil,  where  much  of  it  is  held  as  film 
moisture.  To  use  a  homely  illustration,  let  01  >uppose 
water  is  poured  on  the  head  o£  I  perfectly  bald  person; 
it  quickly  runs  off  from  his  head,  falling  on  his  face 
and  person,  leaving  the  head  scarcely  wet.  If,  on  the 
other  hand,  water  is  poured  on  the  head  of  a  pi 
with  a  heavy  suit  of  hair,  hut  little  runs  off  till  the 
hair  is  thoroughly  wet.  This,  in  a  way,  illustrates  how 
growing  plants  protect  land  from  washing,  and  cause 
rain  water  to  enter  the  soil. 

101.  How  Growing  Plants  Stop  Surface  Evaporation. 
Growing  plants,  besides  protecting  the  soil  from  wash- 
ing, prevent  excessive  surface  evaporation,  which  car- 
ries off  much  moisture  from  exposed  soils.  Sunshine 
■nd  winds  an-  constantly  at  work  evaporating  great 
quantities  of  water  from  exposed  fields,  leaving  the 
soil  dry  and  hard.  On  hare  fields  the  loss  of  water 
through  surface  evaporation  is  enormous.  To  illus- 
trate how  this  loss  takes  place,  let  us  suppose  we  have 
an  ordinary  hucket  half  tilled  with  watc  ;  if  left  open 
t"  nmthini  and  wind  the  water  in  the  bucket  quickly 
evaporate*;  it  passes  through  the  air  which  fills  the 
upper  half  of  the  hucket  and  disappears  into  the  outer 
air  as  water  vapor.  If  the  hucket  be  covered  over  to 
t  it  from  the  wind  and  >un,  much  of  the  evapora- 
tion is  stopped.  Now,  the  toil  is  much  like  a  hucket  half 
full  of  water.  We  have  first  a  layer  of  comparatively 
dry  soil,  that  is  soil  containing  only  film  moisture.  This 
ipondl  to  the  air  in  the  upper  half  of  the  water 
bucket.  Then  we  hav*  I  layer  of  soil  tilled  with  ■ 
and  the  whole  rests  on  a  bottom  formed  by  the  imper- 


104 


ELEMENTS    OF    AGRICULTURE 


vious  stratum  or  layer.  If  the  soil  is  bare  and  un- 
covered to  the  sun  and  wind,  the  water  from  below 
rises  through  the  upper  layer  of  soil  and  evaporates. 
Cover  the  soil  with  either  growing  or  dead  plants  to 
protect  its  surface,  and  the  evaporation  is  stopped,  as 
it  is  in  the  bucket.  Anything  used  to  cover  the  surface 
of  the  soil  to  prevent  evaporation,  or  washing,  is  called 
a  mulch,  and  the  process  is  known  as  mulching. 

It  is  in  the  winter  and  early  spring  months  that 
most  of  the  rains  fall,  and  in  protected  soils  the  excess 
of  moisture  is  stored  up  for  the  use  of  plants  during 
the  drier  months  of  summer.  If,  however,  the  soil 
be  left  bare,  the  winds  and  sunshine  of  spring  evapo- 
rate vast  quantities,  and  when  summer  comes  with  its 
hot,  dry  days  the  growing  plants  find  but  a  poor  supply 
of  water  stored  up  for  their  use. 

102.  Condition  of  Cultivated  Fields. — Now,  what  is 
the  condition  of  many  cultivated  fields  during  the 
season  of  heaviest  rainfall?  Take  the  tobacco  lands, 
for  example;  after  a  crop  of  tobacco  is  gathered  the 
soil  is  left  almost  perfectly  bare.  Tobacco  is  gathered 
so  late  in  the  season  that  no  weeds  can  grow,  and  the 
only  protection  the  soil  has  from  the  washing  rains 
of  winter  is  the  scattered  stubble  from  the  crop  itself. 
The  cotton  lands  of  the  South  fare  but  little  better 
than  the  tobacco  lands ;  their  only  protection  being  the 
dry,  dead  stalks  scattered  over  the  fields.  Often  these 
are  collected  and  burned,  leaving  the  soil  with  no  pro- 
tection for  the  winter.  Wheat  and  oat  lands  fare  much 
better;  for  after  these  crops  are  cut  heavy  growths  of 
weeds  spring  up,  and  these,  when  plowed  under,  supply 


HOW  SOIL8  LOSE  WATER  105 

the  soil  with  i  gnat  mass  of  decaying  organic  matter, 
which  Berrei  to  hold  much  of  the  winter's  ruin,  and 
.•vajH.ration.  Cultivated  BOilfl  that  have 
any  tendency  to  wash  or  leach  should  never  be  left 
ban  to  the  action  of  the  winter  rains. 

Questions 

1.  What  are  fertile  soils?  2.  If  a  soil  fails  to  supply  any 
one  of  the  essential  plant  foods  what  is  it  called?  3.  How 
does  a  soil  become  poor?  4.  Name  two  important  plant 
foods  often  lacking  in  soils.  5.  Why  is  it  that  deserts  pro- 
duce no  plants?  6.  How  are  the  oases  of  deserts  formed 
and  how  may  they  become  fertile?  7.  If  worn  lands  are  left 
uncultivated  for  any  length  of  time  what  sort  of  crops 
spring  up?  8.  How  is  the  supply  of  water  in  soils  renewed? 
9.  How  is  rain  water  held  in  soils?  10.  How  are  plants 
constantly  supplied  with  water?  11.  Why  do  soils  covered 
with  growing  plants  or  the  litter  of  dead  plants  contain 
more  film  moisture  than  bare  fields?  12.  Give  an  illustra- 
tion of  how  plants  protect  soils  from  washing.  13.  Why  do 
lands  that  have  been  cropped  in  tobacco  or  cotton  suffer 
from  washing  and  leaching?  it  Which  as  a  rule  contain 
more  film  moisture,  lands  left  bare  all  winter  or  lands  cov- 
ered with  vegetation? 


106 


ELEMENTS    OF    AGRICULTURE 


CHAPTEE  XX.— How  Soils  Lose  Nitrogen 

103.  Nitrogen  Necessary  to  Fertile  Soils. — Many 
cultivated  soils  become  worn  and  unfit  to  produce 
profitable  crops  through  the  loss  of  their  supply  of 
organic  matter  which  contains  nearly  all  the  nitrogen. 
A  supply  of  nitrogen  is  just  as  necessary  for  growing 
crops  as  a  supply  of  water;  and  the  nitrogen  supply  of 
soils  is  to  a  certain  extent  dependent  upon  the  water 
supply,  because  the  bacteria  which  change  the  protein 
into  soluble  compounds  of  nitrogen  cannot  work  in 
perfectly  dry  soils.  In  order,  then,  that  soils  may  con- 
tain nitrogen,  they  must  contain  a  supply  of  moisture. 
As  cultivated  lands  are  robbed  of  their  water  supply, 
becoming  hard  and  dry,  they  are  at  the  same  time 
being  robbed  of  their  nitrogen.  A  dry  soil  can  supply 
the  plant  with  neither  water  nor  nitrogen,  and  is  said 
to  be  deficient  in  these  two  plant  foods. 

104.  Decay  of  Organic  Matter  Necessary  to  Form 
Nitrogen. — To  contain  a  supply  of  nitrogen  soils  must, 
in  the  first  place,  contain  some  form  of  decaying  vege- 
table or  animal  matter ;  and,  in  the  second  place,  in 
order  that  the  organic  matter  may  decay  and  other 
compounds  of  nitrogen  be  formed,  the  conditions  in 
the  soil  must  be  favorable  to  the  bacteria  which  cause 
the  changes. 

105.  Loss  of  Nitrogen  Through  Cultivation.— On 
wooded  lands  the  leaves  of  the  trees  die,  fall  to  the 
ground  and  go  to  form  humus  in  the  soil;  the  trees 


HOW    8OIL8    LOSE    NITROGEN  107 

themselves  in  their  turn  die,  decay,  and  pass  hack  into 
the  soil;  and  by  this  process  of  gradual  growth  and 
decay  but  little  nitrogen  is  lost.  Hut  the  conditions 
.-in-  very  different  in  cultivated  fields.  Here  quantities 
of  nitrogen-con  tain  in-:  organic  matter  are  each  year 
taken  from  the  soil,  and  but  little  returned.  A  crop 
o!  hay,  for  instance,  weighing  about  2,000  pound*, 
takes  from  the  -oil  about  !.?<><)  pounds  of  organic  mat- 
ter, whit  h  contains  about  twenty-five  pounds  of  nitro- 
gen. And  i  crop  taken  from  the  soil  removes 
I  certain  amount  of  nitrogen.  Nearly  all  of  this  nitro- 
gen comes  from  the  decay  of  organic  matter  in  tb 
and  unit—  fresh  Olgank  matter  be  added  to  replace 
that  used  up,  the  supply  must  in  time  becbmi 
bausted,  and  the  bacteria  of  decay  be  left  without 
material    from    which    to    manufacture   compound-    ol 

nitrogen.  Suppose  ■  crop  remove-  from  the  soil  hrenty- 
five  pounds  of  nitrogen;  if  the  organic  matter  in  the 

soil  contains  about    1  per  cent  of  nitrogen,  Mich  a  crop 

would  require  8,500  pounds  to  supply  ita  nitrogen.    The 

re  'I-  and  itubhle  from  cropf  deeaj  in  the  tOll,  and  are 
converted  into  humus  and  some  compounds  of  nitro- 
gen, hut  they  cannot  supply  enough  nitrogen  to  replace 
that  removed  by  the  crops.  After  each  crop  jg  removed 
the  soil  should  be  supplied  with  OTgank  matter  which 
may  DC  converted  by  the  ha- teria  into  fresh  Supplies 
of  humUS.  After  some  crop-.  BUCh  M  wheat  and 
oats,  crops  of  weeds  spring  up,  which,  when  plowed 
under,  supply  fresh  quantities  of  organic  matter. 

Other  crops.  >uch  tf  bobaCCO  and  cotton,  leave  t! 

with  only  a  few  scattered  roots  and  stubble.     When 


108  ELEMENTS    OF    AGRICULTURE 

crops  of  tobacco  or  cotton  are  removed  year  after  year 
from  the  same  field  and  no  organic  matter  is  added,  the 
soil's  store  of  nitrogen  soon  becomes  exhausted. 

106.  Denitrification. — "But  the  loss  of  nitrogen  in 
soils  occurs  not  only  from  a  decrease  in  the  supply 
of  organic  matter.  The  influence  of  moisture  on  nitro- 
gen compounds  in  soils  has  already  been  mentioned. 
Nitrification  takes  place  only  in  moist  soils;  in  very 
dry  soils  not  only  does  nitrification  cease,  but  there  is 
actually  a  loss  of  nitrogen  or  what  is  called  denitri- 
fication. By  a  process  of  dry  decay  the  nitrogen- 
compounds  in  the  soil  are  broken  up  and  the  nitrogen 
passes  into  the  air  as  free  nitrogen  gas.  .  A  loss  of 
nitrogen  also  takes  place  from  very  wet  soils^and  from 
soils  poorly  supplied  with  air.  The  water  in  wet  soils 
drives  out  the  air,  and  without  a  supply  of  oxygen  no 
nitrates  can  be  formed  from  the  decaying  organic 
matter.  Some  nitrogen  compounds  are  also  washed 
from  the  soil  in  the  drainage  water,  and  some  escape 
as  ammonia  gas.  And  while  the  loss  in  this  way  from 
ordinary  soils  is  not  great,  still  it  is  enough  to  affect 
the  total  supply. 

Is  it  any  wonder,  then,  that  the  cotton  and  tobacco 
lands  become  poor,  and  fail  to  produce  crops  ?  Washed 
and  leached  by  the  winter  rains,  scorched  by  the  sun, 
parched  by  the  winds,  robbed  of  their  water  and  or- 
ganic matter,  how  can  they  produce  crops  ? 

Questions 

1.  How  does  the  loss  of  organic  matter  affect  soils? 
2.  Name   two   very   important  plant   foods.     3.  How   does 


how  soma  lose  nitrogen    *  109 

the  water  supply  of  soils  affect  the  supply  of  nitrogen? 
4.  What  three  things  are  necessary  for  the  formation  of 
nitrogen  compounds  in  soils?  5.  What  becomes  of  the 
dead  leaves  of  trees?  6.  What  effect  do  crops  have  on  the 
supply  of  nitrogen  in  soils?  7.  What  is  denitrincation? 
^.  How  do  dry  soils  lose  nitrogen?  9.  How  do  wet  soils 
lose  their  nitrogen?  10.  Why  do  tobacco  lands  often  suffer 
a  greater  loss  of  nitrogen  than  wheat  lands?  11.  Why  do 
cotton  lands  suffer  a  loss  of  nitrogen? 


110 


ELEMENTS    OF   AGRICULTURE 


CHAPTEK  XXI.— How  Soils  Lose  Mineral 
Matter 

107.  How  Cultivation  Removes  Mineral  Matter  from 
the  Soil. — Soils,  become  impoverished  from  careless 
cultivation,  which  causes  a  loss  of  water  and  nitrogen. 
They  may  also  become  impoverished  through  the  ex- 
haustion of  their  supply  of  phosphoric  acid,  potash  and 
lime.  How  this  occurs  may  be  understood  from  the 
fact  that  each  crop  gathered  from  the  soil  uses  up  for 
its  growth  and  takes  with  it  just  so  much  phosphoric 
acid,  potash  and  lime.  A  crop  of  cotton,  lint  and  seed, 
weighing  about  1,000  pounds,  takes  from  the  soil  about 
6f  pounds  of  phosphoric  acid  and  10  pounds  of  potash. 
One  thousand  pounds  of  tobacco  leaves  take  from  the 
soil  about  3.4  pounds  of  phosphoric  acid  and  40  pounds 
of  potash.  One  thousand  pounds  of  hay  take  about 
3  pounds  of  phosphoric  acid  and  12J  pounds  of  potash; 
and  so  each  crop  takes  from  the  soil  varying  amounts 
of  mineral  plant  food. 

If  year  after  year  so  much  of  these  plant  foods  are 
taken  away  and  none  returned,  the  supply  must  become 
exhausted.  As  a  matter  of  fact,  the  available  supply 
does  often  become  exhausted. 

108.  Phosphates  in  the  Soil. — Phosphorus  exists  in 
the  soil  in  several  forms;  combined  with  certain  pro- 
portions of  calcium  and  oxygen  it  forms  a  compound 
soluble  in  water,  and  in  this  form  is  available  as  plant 
food.    Were  all  the  phosphorus  in  the  soil  in  this  form, 


HOW  SOILS  LOSE  MINERAL    MATTER  111 

what  the  plants  did  not  osc  would  toon  be  gashed  out 

by  rains  and  the  soil  left  with  none  at  all.  Fortunately, 
most  of  the  phosphorus  in  the  Boil  ii  combined  with 
inm  and  aluminum,  in  which  form  it  is  nearly  insolu- 
ble in  water  rod  una\  ailahlc  for  plan!-.  IJy  MOM  pro- 
cesses in  the  soil,  probably  the  action  of  the  acids  in 
humus,  the  insoluble  phosphsteS  axe  gradually  being 
converted  into  soluble  compounds  which  become  food 
for  growing  plants.  This  change  is  so  gradual  thai 
jjnsl  about  enough  soluble  phoephatee  arc  made  each 
year  to  supply  the  demand  of  the  yearly  growth  of 
nature's  crops.  Nature  allows  her  crops  to  go  on 
growing  year  after  year,  but  little  in  the  way  oi  plant 
food  being  removed  from  the  soil;  so  each  year  only 
enough  plant  food  is  required  to  supply  the  season's 
growth,  and  the  supply  is  always  ahundant. 

On  cultivated  lands  a  CTOp  is  usually  gathered  each 
\iiii.  and  with  it  go  from  the  soil  the  BOluble  phos- 
phate- it  hai  taken  np  in  growing.  The  next  year  the 
soil  must  supply  nmn  plant  food  for  the  season's  crop, 
and  so  this  goes  on  each  year.  The  formation  of  solu- 
ble phosphates  in  many  soils  is  so  slow  that  there  is 
not  sufheient  to  supply  this  constant  demand,  and  men 
soils  are  said  to  be  deficient  in  phosphoric  acid.  V.  i  \ 
often  they  h;i\e  a  large  store  of  insoluhle  phosphates, 
but  are  unable  to  manufacture  the  soluble  compounds 
fast  enough  to  supply  the  demand  of  the  crops.  The 
great  store  of  phosphates  contained  in  most  soil-  ia 
shown  by  the  following  figures:  An  sen 
square  feet;  then  if  the  soil  be  twelve  inches  deep,  we 
have  for  an  acre  of  ground  13,560  cubic  irface 


112  ELEMENTS    OF   AGRICULTURE 

soil.  Now,  ordinary  soil  weighs  about  90  pounds  to  the 
cubic  foot.  In  other  words,  an  acre  of  soil  twelve  inches 
deep  weighs  3.920,400  pounds.  If  such  a  soil  contains  .1 
per  cent  of  phosphoric  acid  it  would  yield  3,920  pounds 
to  the  acre.  Poor,  sandy  soil  contains  sometimes  only 
0.05  per  cent  phosphoric  acid,  or  1,960  pounds  to  the 
acre.  Now,  a  crop  of  1,000  pounds  of  tobacco  removes 
3.4  pounds  of  phosphoric  acid.  So  an  acre  of  good 
soil  contains  enough  phosphoric  acid  to  supply  about 
1,150  crops,  of  1,000  pounds  each,  of  tobacco,  and  poor 
sandy  soil  has  enough  for  about  575  crops  of  the  same 
size.  These  figures  do  not  mean  that  the  soil  con- 
taining .1  per  cent  of  phosphoric  acid  could  be  cropped 
in  tobacco,  continuously,  for  1,150  years  without  be- 
coming -exhausted,  for  tobacco  requires  other  elements 
besides  phosphoric  acid ;  but  they  do  show  what  a  great 
store  of  phosphates  the  soil  contains  which,  if  properly 
used,  will  furnish  many  crops  with  food.  But  we  have 
considered  only  the  first  twelve  inches  of  soil;  the  roots 
of  most  crops  penetrate  to  greater  depths  than  twelve 
inches;  the  roots  of  the  cotton  plant  have  been  known 
to  reach  into  the  subsoil  between  seven  and  eight  feet. 
The  roots  of  wheat  plants  often  reach  a  depth  of  four 
or  even  five  feet.  As  the  subsoil  often  contains  nearly 
as  much  of  phosphates  as  the  soil,  such  crops  have 
much  larger  supplies  of  this  food  to  draw  on  than  are 
contained  in  the  first  twelve  inches.  There  is,  of  course, 
some  phosphoric  acid  lost  from  the  soil  through  leach- 
ing, but  as  most  of  the  phosphates  are  very  insoluble 
this  loss  in  well  cultivated  soil  is  but  small.  An  ordi- 
nary soil,  if    carefully    cultivated,    may    be    steadily 


H<>\V    SOILS    LOSE    MINERAL    MAIM  .1:  113 

cropped  for  many  generations  without  exhausting  its 
total  rapply  of  phosphoric  acid,  but  its  supply  <>f  avail- 
able phosphates  may  be  exhausted  with  one  <>r  two 
The  question,  then,  ii  how  must  the  soil  be 
•1  in  order  that  its  store  of  phosphates  may  be- 
available  as  food  for  cultivated  crops.     It  il  ditli- 
cult   to  answer   this   question   satisfactorily,  for  the 
solubility  of  the  soil  phosphatei  is  influenced   by  a 
■umber  of  different  conditions  in  the  soil,  none  of 
which  is  perfectly  understood    Hut  it  is  known  that 
the  amount  of  soluble  phosphoric  acid  in  soils  ii  in- 
ftuenced  to  i  great  extent  by  the  amount  of  humus  it 
contain-.    The  so-called  insoluble  phosphates,  though 

almost  insoluble  in  water,  are  acted  on  bj  even  \\.-ak 
eeida,  and  by  them  converted  into  compounds  soluble 
in   water.      II minis  contains  a'  number  of  weak   acids, 

and  they  undoubtedly  ad  on  the  insoluble  phosphates 
in  the  soil,  conrerting  them  into  forms  suitable  for 

plant    food.      Here  we  have  another  illustration  of  the 

value  of  soil  bacteria,  and  the  importance  of  careful 

cultivation.  Soil  hacteria  supply  nitrogen  for  grow- 
ing crops;  they  also  hare  much  to  do  with  supplying 
the  available  phosphates.  Some  salts  in  the  soil  proba- 
bly affect  the  supply  «»f  soluble  phosphates,  but  their 

action   tl  not   SO  important   BJ  the  action  of  humUS. 

109.  Potash  in  the  Soil. — The  supply  of  potash  in 
the  soil  cornea,  as  ire  bare  already  learned,  principally 

from  the  decay  of  rOCKS  railed  feldspars,  in  which  the 
potash  il  Combined  with  Silica  to  form  what  are  tailed 
potassium  lilicatei      \\  hen  these  rock-  decay  and  form 

sella,  some  of  the  silicatei  combine  with  ebj  and  form 
8 


114  ELEMENTS    OF    AGRICULTURE 

what  are  called  double  silicates,  which  are  much  less 
soluble  in  water  than  the  ordinary  silicates.  In  this 
form  they  are  preserved  in  the  soil,  and  are  said  to  be 
fixed.  A  good  clay  loam  contains  about  .5  per  cent  of 
potash  and  sandy  soils  about  .1  per  cent.  This  would 
give  for  the  clay  soil  19,602  pounds  of  potash  per  acre 
of  surface  soil,  and  for  the  sandy  soil  3,920  pounds  of 
potash.  Such  a  clay  soil  could  furnish  enough  potash 
for  nearly  500  crops  of  tobacco  of  1,000  pounds  per 
acre,  or  390  crops  of  hay  of  two  tons  per  acre.  The 
sandy  soil  could  supply  potash  for  about  100  such  crops 
of  tobacco  and  nearly  eighty  such  crops  of  hay.  But 
this  store  of  potash  is  not  all  available  for  crops;  a 
large  part  of  it  is  locked  up  just  as  the  phosphates  are, 
and  the  soil  parts  with  it  very  slowly.  These  unavail- 
able compounds  of  potash  become  available  for  plants 
in  much  the  same  way  as  the  phosphates,  that  is,  by 
the  action  of  the  weak  acids  of  humus.  These  acids 
form  compounds  with  the  potash  which  are  called 
humates,  and  which  are  readily  taken  up  by  plants. 
Here  again,  through  manufacture  of  humus,  the  soil 
bacteria  are  of  great  importance. 

110.  Lime  in  the  Soil. — Some  soils  may  be  deficient 
in  their  supply  of  lime,  which  is  an  essential  plant  food. 
Besides  being  an  essential  plant  food,  lime  is  of  great 
value  in  soils  because  of  its  action  upon  humus. 
Humus,  as  you  have  already  been  told,  contains  a  num- 
ber of  weak  acids  which  act  on  the  phosphates  and 
potash  compounds  in  the  soil.  These  humus  acids  also 
combine  with  the  lime  in  the  soil,  and  by  their  action 
on   the   lime,    the   phosphates   and   the    potash    com- 


HOW    SOILS    LOSE    MINERAL    MATTER  11"' 

pounds,  the  acid  properties  of  humus  are  destroyed. 
If  a  soil  contains  no  lime  the  -mail  quantities  of  phos- 
phates or  potash  compounds  usually  present  are  not 
■ufficienl  to  combine  with  all  the  acids  of  humus,  which 
insequence  go  on  accumulating  until  the  soil  be* 
comes  decidedly  acid.    Now.  an  A  these  humus 

acids  are  harmful  to  the  roots  of  growing  plants,  re- 
tarding their  growth.  Not  only  arc  they  injurious  to 
growing  plants,  hut  thcv  arc  harmful  to  the  hactcria 
that  form  humus.  An  animal  compelled  to  live  in 
an  accumulation  of  its  own  manure  Mitfcrs  in  health. 

So  tic  ria  <>f  decay,  if  compelled  t<>  live  in  an 

excess  of  the  acids  which  they  form,  sulTer  and  cease 
to  work.    Lime  sets  as  i  cleansing  >r  the  hac- 

tcria <>f  decay,  by  absorbing  and  destroying  the  vraste 

products  thcv  produce  in  the  form  of  acid-.     A  n 
ahle  deficiency  of  lime  in  soils  is  shown  by  an  accumu- 
lation  of  ;ieid*. 

111.  Life  in  the  Soil. — Most  persons  look  on  the  soil 
iplv  a  max  of  dead  mineral  matter  and  decaying 

parts  of  plants  and  animals.  Hut  the  soil  is  far  from 
being  a  (had  mass.     It   is  the  home  of  countless  mil- 

ol  DUS]   u<»rk>  ria.  earth  worms  and  : 

forms  of  many  kinds.     It  is  a  great  workshop  in  which 

lief  workers  are  the  little  soil  hactcria.     It  is  their 

business  t<>  destroy  the  gank  matter,  mamifac- 

tnring  therefrom  valuable  compounds  of  humus  and 

en,  and  producing  adds  which  change  in-oluble 
compounds  of  phosphorus  and  potash  into  plant  food; 
in  short,  to  keep  the  soil  alive.  The  material  with 
which  the  bacteria  work  are  dead  organic  matter,  water, 


116 


ELEMENTS    OF    AGRICULTURE 


air  and  heat;  and  from  these  they  supply  the  world 
with  food.  Like  all  good  workers  they  demand  a  good 
supply  of  material,  and  a  comfortable  shop  well  sup- 
plied with  fresh  air  and  water.  A  soil  without  bacteria 
is   as   dead  as   a  desert,  and   incapable   of  producing 


Questions 

1.  How  does  the  loss  of  mineral  matter  affect  the  fertility 
of  soil?  2.  Name  three  mineral  elements  which  sometimes 
become  exhausted.  3.  About  how  much  phosphoric  acid  is 
removed  from  the  soil  by  500  pounds  of  ordinary  hay? 
4.  How  are  the  unavailable  phosphates  changed  into  plant 
food?  5.  Why  is  it  an  easy  matter  to  exhaust  the  supply 
of  available  phosphates  in  ordinary  soil?  6.  Why  is  it  that 
available  phosphates  are  not  held  in  the  soil?  7.  Explain 
why  the  supply  of  phosphates  in  the  soil  is  not  exhausted. 
8.  Why  do  cultivated  crops  take  from  the  soil  more  plant 
food  than  crops  growing  naturally?  9.  How  far  do  the 
roots  of  most  plants  penetrate  the  soil?  10.  How  does 
potash  in  the  soil  become  available  to  plants?  11.  What 
changes  the  unavailable  potash  into  available  compounds? 
12.  How  is  lime  useful  to  the  bacteria  in  the  soil? 

PROBLEMS 

1.  If  a  soil  weighs  100  pounds  to  the  cubic  foot  and  con- 
tains 0.15  per  cent  of  phosphoric  acid,  how  many,  pounds  of 
phosphoric  acid  are  contained  in  an  acre  of  such  soil  12 
inches  deep? 

2.  Calculate  the  amount  of  potash  in  an  acre  of  soil  12 
inches  deep  when  it  weighs  95  pounds  per  cubic  foot  and 
contains  0.3  per  cent  potash? 


CULTIVATION    OF    SOW  H7 


CHAFFER    XXII.— Cultivation  01  Soils 

112.  Why  Soils  arc  Cultivated.— All     fertile 
produce  naturally  an  abundant  growth  of  plants.    This 

growth  cornea  from  the  seed  or  roots  of  the  many 

plants   which  grow    naturally    in    the   soil.      Th( 
of  such  plants  are  scattered  over  the  surface  <»f  the 
soil  by  various  meant.    Many  rot,  many  arc  eaten  by 
birds  and  animals,  ami  only  i  few  of  the  total  number 
ever  grow;  but  the  supply  of  §eed  la  bo  greal  thai 
after  allowing  for  all  that  arc  destroyed  there  ere 
enough  left  to  produce  many  plants.     Man  groi 
his  use  crops  of  many  kinds  of  plants,  most  of  which 
come  from  seed.     If  the  seed  of  these  crops  useful  to 
man  arc  merely  Scattered  OVf*  the  surface  of  unculti- 
vated soil,  many  of  them  grow,  but  most  of  them  are 
destroyed,  and    such    methods  of    crop    growing  are 
seldom  profitable.    It  baa  been  found  mnch  better  to 

bury  the  seed  below  the  surface  of  the  ground,  where 
they  are  better  protected  from  the  agents  which  de- 
stroy them.  In  order  to  phmt  seed  UM  <  cssfully  the 
surface   of   the   ground    mu>t    be    prepared    to    re 

them,  and  the  more  thorough   the  preparation   the 

greater  the  number  of  seed  that  grow  ami  the  b 
the  plants  they  produce.  The  various  method-  of  pre- 
paring soils  fen  lanting  are  known  as  CULTIVA- 
TION. Not  only  m  d  to  prepare  them 
for  seed  planting,  but  they  arc  often  cultivated  to  aid 
growing  crops  in  obtaining  their  food. 


118  ELEMENTS   OE   AGRICULTURE 

We  usually  think  of  cultivation  as  meaning  the  pro- 
cess of  pulverizing  the  soil's  surface  by  plowing, 
spading,  rolling,  etc.,  and  these  are  the  ordinary 
methods  employed.  But  there  are  other  methods  of 
cultivation  besides  mere  surface  cultivation,  and  two 
that  are  oftentimes  of  great  importance  are  drainage 
and  irrigation.  They  both  affect  the  water  supply  of 
soils,  and  water  is  probably  the  most  important  of  all 
plant  foods. 

113.  Drainage. — In  Chapter  XIX  you  were  told  how 
soils  lose  their  water  supply,  becoming  dry  and  barren ; 
on  the  other  hand,  there  .are  soils  that  contain  too 
much  water.  In  many  places  the  impervious  stratum 
lies  near  the  surface  of  the  soil,  and  the  soil  being  shal- 
low, becomes  quickly  filled  with  free  water.  If  now 
the  impervious  stratum  has  little  slope  the  free  water 
drains  away  very  slowly,  and  the  only  way  the  soil  is 
freed  from  it  is  through  surface  evaporation,  which, 
if  the  soil  be  covered  with  vegetation,  is  slow.  The 
drainage  of  the  soil  being  poor  and  the  surface  evapo- 
ration small,  water  accumulates  and  keeps  the  soil 
constantly  wet.  It  is  in  this  way  that  swamps  and 
marshes  are  formed.  The  excessive  amount  of  water 
may  be  drained  from  such  soils  by  digging  ditches 
through  which  the  water  may  flow  into  some  creek  or 
river.  As  open  ditches  interfere  with  surface  cultiva- 
tion, they  are  usually  made  into  what  are  called  under- 
drains.  In  the  bottom  of  the  ditch  a  little  culvert  is 
built  of  stone,  brick  or  wood,  the  joints  being  left  open. . 
The  ditch  is  then  filled  in  with  earth,  and  the  under- 
drain  is  completed.    The  free  water  in  the  soil  enters 


119 


the  drains  through  the  cracks  and  joints,  which  are 
properly-  l«-f t    open,     dnderdraina   arc   often    called 

blind-drains.  In  place  of  a  built-up  drain  COOTO  tiles 
are  often  \\-<-i\.  Tiles  are  short  piecei  of  clay  pipe, 
which  air  looeelj  fitted  together  in  the  bottom  of  the 

drain.      Such   drains  are  called   tile-drains  and.   a-    in 
the  ordinary  drain,  the  water  enters  through  the  joints. 
.     K    ihoWl   an    ordi- 
nary   blind-drain    end 
Pig.   L8  a  tile-drain. 

Beaidei  removing  th  i 

excess  of  water  and  ren- 
dering the  soil  lit  for 
surface      cultivation. 

drainage   is  of   benefit 

Kio.  17.— Stone-    to    the    SOU*     in    several       PM.   ls-TUe- 
dram  .  .  .  ..    drain, 

ways.     It  make-  the  soil 

wanner  by  presenting  the  63  iporation. 

It  allows   the   roots  of  plants  to   penetrate   the   soil    to 

greater  depths;  for  the  roots  of  most  cultivated  crops 

cannot  grow  in  a  soil  saturated  with  water.     It  Opens 

up  the  soil  to  the  air  which  supplies  the  root) 

tag  plants  with  oxygen,  and  sometimes  with  nitrogen. 

In   many    parti   of   our  country   are   irreat    areas  of 

swampy  lands  which,  when  properly  drained,  may  bc- 

irming  lands,  tithing  a  thor 

drainage  system  the  small  country  <>f  Holland  has 
added  to  its  territory  over  ;uare  miles  of  rich 

tanning  land  that  was  once  an  uninhabitable  swamp. 
114.  Irrigation. — Irrigation  i-  th'  of  drain- 

age,  as.   it    is    the    addition,    by    artificial    mea: 


120 


ELEMENTS    OF    AGRICULTURE 


water  to  dry  soils.  The  water  is  usually  added  to  the 
soil  by  means  of  open  ditches.  One  main  channel  may 
supply  a  number  of  smaller  ditches  intersecting  the 
field  to  be  irrigated,  and  which  need  be  only  a  few 
inches  deep — little  more  than  an  ordinary  furrow. 
These  irrigation  ditches  are  filled  with  water  froln 
some  tank  or  pond,  much  of  which  soaks  into  the  soil. 
It  is  not  necessary  that  these  ditches  should  be  kept 
filled  with  water,  for  they  may  be  filled  from  time  to 
time,  and  the  water  allowed  to  soak  out.  This  prac- 
tice is  called  surface  irrigation  to  distinguish  it  from 
sub-irrigation,  by  means  of  which  the  water  is  added 
to  the  subsoil.  Underdrains,  usually  tile,  are  put  in 
with  the  slope  running  in  the  opposite  direction  to  ordi- 
nary drains,  and  they  are  occasionally  flooded  with 
water,  which  soaks  through  the  joints  into  the  soil. 
This  is  the  most  perfect  system  of  irrigation,  because 
there  is  little  or  no  loss  of  water  through  surface 
evaporation.  Unfortunately,  it  is  much  more  costly 
than  surface  irrigation,  and  for  this  reason  but  little 
practiced  except  in  gardens  or  hothouses. 

The  flooding  of  the  Nile  Valley  is  an  illustration  of 
natural  irrigation.  This  great  river  annually  rises  far 
beyond  its  banks,  flooding  a  great  stretch  of  country; 
the  mud  it  brings  with  it  enriches  the  soil,  and  much 
water  is  at  the  same  time  added.  The  river  bottoms 
are  thoroughly  irrigated  once  a  year,  and  are  noted  for 
their  fertility.  There  are  in  our  own  county  great 
areas  of 'soil  that  have  been  robbed  of  their  moisture. 
The  rainfall  is  too  uncertain  to  make  good  the  loss, 
and  it  is  only  by  irrigation  that  most  of  the  soil  may 


ct'i.nv  1 1 1..\   of  soils  121 

be  made  fertile  In  many  parts  of  tin-  w.-i  large  tracts 
of  country  once  parched  d<  •    being  com. 

into  fine  tanning  land  by  means  of  irrigation. 

Questions 

1.  What  becomes  of  most  seed  simply  scattered  on  the 
surface  of  the  soil?  2.  Why  is  it  usually  found  more  pro- 
fitable to  bury  the  seed?  3.  Why  is  it  better  to  prepare  the 
soil  before  planting  seed?  4.  By  what  name  do  we  call  the 
process  of  preparing  the  soil  for  planting?  5.  What  is 
meant  by  cultivation?  6.  Name  two  important  methods  of 
cultivation  that  influenco  the  water  supply  in  soils. 
7.  What  is  meant  by  drainage?  8.  Explain  how  a  swamp 
or  marsh  is  formed.  9.  How  are  open  drains  made? 
10.  What  is  an  underdrain?  11.  What  is  a  tile-drain? 
IS,  How  does  drainage  benefit  the  soil?  13.  What  is  irri- 
gation? 14.  How  does  surface  irrigation  differ  from  sub- 
Irrigation?  16.  Which  is  t!x  more  perfect  system?  16.  Wh> 
is  it  less  used?  IT.  In  what  part  of  the  United  States  it 
irrigation  most  practiced? 


1^2  ELEMENTS    OF    AGRICULTURE 


CHAPTER  XXIII.— Cultivation  of  Soils 
(Continued) 

115.  Surface  Cultivation  of  Soils. — Surface  cultiva- 
tion means  the  pulverizing  of  the  surface  soil  prepara- 
tory to  planting  seed,  or  else  the  working  of  the  crop 
after  it  has  begun  to  grow.  The  preparation  of  the 
soil  for  seed  planting  is  usually  accomplished  by  plow- 
ing. Spading,  while  it  is  more  efficient  than  plowing, 
is  too  expensive  to  practice  on  a  large  scale,  and  is 
resorted  to  only  for  gardens. 

116.  Plowing. — Some  form  of  plowing  is  almost  the 
universal  method  of  cultivation,  and  the  plow  most 
generally  used  in  this  country  is  the  turn  plow;  that 
is,  a  plow  which  turns  over  the  first  four  to  six  inches 
of  soil.  One  disadvantage  of  this  form  of  plow  is  that 
it  cuts  usually  to  the  same  depth,  and  after  many 
plowings  the  soil  over  which  the  bottom  of  the  plow 
is  dragged  is  apt  to  become  packed,  forming  what  is 
called  a  hard-pan.  This  hardened  layer  of  earth  is 
difficult  for  the  roots  of  plants  to  penetrate,  and  also 
interferes  with  the  movement  of  water  in  the  soil. 
It  may  be  broken  up  by  changing  the  depth  of  plowing, 
which  can  be  most  easily  effected  by  the  use  of  the 
subsoil  plow.  The  subsoil  plow  follows  immediately 
in  the  furrow  of  the  ordinary  plow,  and  breaks  up  and 
loosens  the  subsoil.  Subsoil  plowing  is  of  benefit  when 
the  subsoil  has  a  tendency  to  become  hard, , 


iv  \  il..\    OF    SOILS 


123 


The  plow  doei  n«»t  always  j»ut  the  soil  into  proper 
condition  for  planting.     After  plowing,  ill  are 

full   of    lumps    ami     clods,    which,   unless     broken    up, 

seriously  interfere  with  the  growth  <>f  the  rool 

young  plants.     Such   -oils  arc  harrowed  or  rolled    for 

the  purpose  of  breaking  ap  the  clods  and  producing 
an  even  surface. 

117.  Cultivating   the   Soil   for   Planting. — The  pri- 
mary  object     in    sur- 
face cultivation  is  to 

prepare     the     soil    for 

leed    planting.     The 

pulverized  surface  of- 
fers a  safe  place  f«»r 
the  germination  of  the 
.  and  i-  easily 
pone  t  rat  ed  by  the 
JOUng  roots.  A  hard, 
lumpj     soil,      on     the 


Fio.  19— Plant 


Via.  30— Plan  t 


Cfrow'lnR  In  shal      other      hand,     offers    U    growing    j 
ow.     |H»orly    cultJ-  frell-eu  1  t  i  v  a  t  i- d 

vawd  sou.  poor  shelter  for  seed,  •°o« 

and  retards  the  development  of  the  roots,  producing 
.  dotty  plants.  The  toots  of  meal  cultivated  plants 

are   soft   and    delicate,    and    are    entirely     unable    to 

penetrate     hard     ftoOs;     under    Mich     condition.-     they 

grov  slowly  and  tail  to  supply  the  plant  with  the 
necessnry  for  it-  perfect  development  Fig.  19  i 
>«iit-  a  plant  growing  in  a  ihallow,  poorly  cultivated 

soil,   and    Fig.    V<>    represent-    the   same    kind   of   plant 

in  a  deep,  well-cultivated  soil. 

\ 

f  UNlVtRSITT 


Of 


124  ELEMENTS    OF    AGRICULTURE 

118.  Effect  of  Cultivation  on  the  Water  Supply  of 
Soils. — Besides- preparing  the  soil  for  the  development 
of  plant  roots,  cultivation  has  a  marked  effect  on  the 
water  supply  of  soils  by  increasing  the  number  and 
reducing  the  size  of  the  soil  particles.  The  effect  of  the 
number  and  size  of  the  soil  particles  on  film  moisture 
has  already  been  described  in  Chapter  XVII,  and  the 
effect  of  drainage  on  the  free  water  in  Chapter  XXII. 

119.  Aeration. — Surface  cultivation  also  admits  a 
freer  circulation  of  air  in  the  soil,  by  making  the  sur- 
face more  open  or  porous,  thus  supplying  oxygen  for 
the  roots  of  plants  and  for  the  soil  bacteria. 

120.  Cultivation  Destroys  Insects  and  Weeds. — Of 
the  many  kinds  of  insects  that  feed  on  cultivated  crops 
there  are  a  number  that  build  their  nests  in  the 
ground,  where  their  eggs  are  deposited  to  be  hatched 
out  by  the  spring  sunshine.  Cultivation  destroys  these 
nests,  bringing  many  insects  and  their  eggs  to  the  sur-* 
face,  where  they  are  eagerly  devoured  by  birds  or  killed 
by  exposure  to  the  weather. 

Many  soils  are  covered  by  a  growth  of  weeds  which, 
when  plowed  under,  rot  and  add  to  the  soil  a  supply 
of  humus  and  nitrogen.  If  left  to  grow  these  weeds 
seriously  interfere  with  the  growing  crops. 

121.  When  to  Cultivate.^— There  is  great  difference 
of  opinion  as  to  whether  soils  to  be  planted  in  the 
spring  should  be  plowed  in  the  fall  and  allowed  to  lie 
bare  all  winter,  or  else  plowed  a  short  time  before 
planting  the  crop.  As  a  matter  of  fact,  the  time  of 
plowing  should  be  regulated  by  the  character  of  the 
soil.    Soils  that  have  a  tendency  to  wash  should  never 


CTI.I  l\    \ 1  -•"» 

be  left  hare  during  tin*  winter,  but  should  be  by  some 
means  protected   from  the  winter  rains.     Then 

I.  \\    soils    that    will    not    lie    improved    hv    having    their 

surface  protected  during  the  winter  months  by  growing 

CTOpfl  or  mulches,      llcaw   clay   -oils  may,  howe\er.   he 

improved  hv  fall  plowing;  ia  they  often  have  a  ten- 
dency U)  form  clods  or  lumps  which  are  broken  up 
during  the  winter  by  the  action  of  the  weather.     Fall 

plowing  is  also  of  benefit  by  destroying  insects  rod 
weeds. 

122.  Cultivating  the  Crop. — After  crops  have  begun 
to  grow   Ihev  are  often   cultivated    for  the   pUTpOl 

destroying  weed-  which  spring  up  elong  with  the  crop 

and  rob  the  soil  of  much  food.     Such  cultivation  should 
consist    in    frequently   stirring   the  surface   of   th. 
with  a  cultivator,  harrow,  or  hoe,  care  being  taken  not 

to  cultivate  deep  enough  to  Injure  the  roots  of  the 
growing  crop.  Plowing  corn  and  hoeing  tobacco  or  cot- 
ton are  familiar  operation-  to  til  who  have  spent  any 

time  en  a  farm.    Now.  besidei  destroying  weeds,  tins 

surface  cultivation  tfl  of  much  henetit  to  the  crop  in  an- 
other way.     Surface  evaporation  of  film  moist \\r<  . 

remember,  take-  pine  rapidly  from  i,  and 

the  method  of  cultivation  of  the  thr.  just  men- 

1  lesvet  the  soil  somewhat  hare;  at  least  such  is 

the     pass    during   the   first    feu    months   of   the   i 

growth    The  surface  cultivation  itiri  up  the  tirst  few 

which  dry  out  rapidly  and  form  a  sort 
of  natural  covering  or  mulch  for  the  soil.  It  thus 
serves  as  a  check  on  surface  evaporation,  and  has  the 


126 


ELEMENTS    OF    AGRICULTURE 


same  effect  as  covering  the  soil  with  a  layer  of  dry 
earth. 

Crop  cultivation  also  serves  to  open  up  the  soil  to 
a  freer  circulation  of  the  air  which  supplies  oxygen,  to 
the  growing  roots. 

123.  Terracing. — There  are  two  methods  of  treating 
soils  to  prevent  excessive  surface  washing  that  are 
especially  applicable  to  steep  hillsides.  Terracing 
means  that  the  hillside  is  so  cultivated  as  to  form  a 
series  of  large  steps  or  terraces,  and  the  slope  between 


Fig.  21.— Terraced  hillside,  with'  ditches  for  irrigating; 
fruit  trees  planted  on  the  terraces. 

the  terraces  planted  in  grass  or  some  thick-growing 
crop  to  prevent  .washing.  Fig.  21  shows  how  a  hillside 
may  be  terraced  and  planted  in  trees.  This  is  of  course 
an  expensive  method  of  protecting  hills,  and  a  simpler 
and  equally  as  applicable  method  is  to  construct  a  suc- 
cession of  smaller  terraces  about  the  hill — two  good 
furrows  forming  a  terrace  a  foot  or  two  wide  are  suffi- 
cient. These  are  allowed  to  grow  up  in  grass  and  serve 
to  check  the  formation  of  gullies. 

Questions 

1.  What  is  meant  by  surface  cultivation  of  soils?  2.  What 
is    the    most    common    method    of    surface    cultivation? 


CULTIVATION    OP   SOILS  127 

S.  What  is  the  most  common  form  of  plow?  4.  Explain 
one  serious  disadvantage  of  this  form  of  plow.  5.  How 
may  this  trouble  be  remedied?  6.  Why  will  not  a  plant 
grow  well  in  a  coarse,  rough  soil?  7.  Why  do  plants  as  a 
rule  develop  best  in  well  cultivated  soils?  8.  What  effect 
has  good  cultivation  on  the  film  moisture  in  soils?  9.  How 
does  cultivation  affect  the  oxygen  supply  of  soils?  10.  How 
does  cultivation  destroy  weeds  and  insects?  11.  How  may 
fall  plowing  benefit  heavy  clay  soils?  12.  Under  what  con- 
dition is  it  advisable  to  plow  in  the  fall  soils  that  are  to 
be  planted  in  spring?  13.  Why  are  young  crops  culti- 
vated? 14.  How  does  surface  cultivation  prevent  surface 
evaporation?  15.  What  is  meant  by  terracing?  16.  How 
does  terracing  protect  soils? 


128  ELEMENTS    OF    AGRICULTURE 


PART  IV.-MANUEEgi 


CHAPTER  XXIV. — Classification  of  Manures 

124.  Definition  of  Manures. — The  dictionary  defines 
a  manure  as  anything  that  may  be  applied  to  a  soil  to 
make  it  more  fertile. 

Manures  may  be  conveniently  divided  into  two 
classes,  natural  manures  and  manufactured 
manures;  the  latter  class  being  called  commercial 

FERTILIZERS. 

125.  Natural  Manures. — These  are  substances  occur- 
ing  naturally,  and  which  are  not  manufactured  spe- 
cially for  use  as  manure.  Marl,  gypsum  and  some 
forms  of  potash  salts  are  natural  -manures,  as  are  wood 
ashes,  swamp  muck,  dead  leaves  or  straw,  and,  best 
of  all,  stable  manure.  There  are  some  by-products, 
such  as  cottonseed-meal  and  sulphate  of  ammonia, 
which,  while  not  manufactured  specially  for  fertilizers, 
are  usually  classed  with  other  manufactured  products. 

1.  Marl  is  a  kind  of  soft  earth,  a  mixture  of  sand 
with  varying  proportions  of  clay  and  carbonate  of 
lime,  with  sometimes  additions  of  potash  and  .phos- 
phoric acid.  Some  kinds  found  in  New  Jersey  and 
Virginia  are  rich  in  phosphoric  acid  and  potash,  and 
are  much  used  as  a  fertilizer.  Marls,  as  a  rule,  are 
used  only  in  the  immediate  neighborhood  of  their 
occurrence.  Being  bulky,  the  cost  of  transporting  them 


CLASSIFICATION     °K     MAM   IMS  129 

is  too  great  to  yield  a  profit  from  their  -ale.    The  chief 
use  of  marls  is  to  supply  linn*  to  .-oils. 

2.  Gypfnm,  which  when  ground  up  a  known  as  land- 
plaster,  is  a  compound  of  calcium,  oxygen  and  sulphur. 
It  is  a  soft,  white  nibstancc  easily  ground  op 

powder,      QjpeVJB   is  used   to  supply   lime   to  -oils. 

Wood  eahes  were  formerly  much  used  as  a  fertili- 
zer, hut  now  as  wood  has  become  more  rateable  less 
ashes  are  produced  than  formerly.  Wood  ashes  are 
exceedingly  valuable  for  manure,  as  they  contain  all 

the  mineral  elements  necetsaty   for  plant   food.     W 1 

ashes  all  contain  i  notably  large  proportion  of  potash. 
I.   Swamp  muck  fa  the  rich,  dark  mud  that  aceumu- 

Latec  in  the  bottom  of  ponds  and  Bwampa.    It  i-  rich 
in  organic  matter,  and  is  sometime!  applied  to 
pour  in  humus. 

.*».  v.  old  i>  formed  by  decaying  leaves  and 

branches  from  foreai  trees,  and  ia  oaed  f<»r  enriching 
gardens  and  botbi 

'     Dead  leaves,  straw  and  such  waste  prodncts  nay 
all  l>e  used  to  supply  organic  matter  t«.  loila, 

*    Barnyard    manure  U  often   classed    with   stable 

manure,  though  really  quite  a  diiTerent  product.  It  is 
the  mamm  that  accumulates  in  small  lot-  where  cattle 
are  kept   and   fed.  and  COnSlstl  <>f  the  dropping!  <>f  the 

cattle  mixed  with  the  bedding  mpplied  them.     The 

\alue   of  such    manuie   depettdl    both    <>n    the   bedding 

and  the  drainage  of  the  l"t.    When  the  bedding  is  thin, 

and  the  lot  well  drained,  rain  water  washes  away  many 
valuable  product*  from  the  manure.     If,  on  the  other 
9 


130  ELEMENTS    OE   AGRICULTURE 

hand,  -the  lot  is  well  bedded  and  undrained,  the  result- 
ing manure  is  nearly  equal  in  value  to  stable  manure. 

8.  Stable  manure  accumulates  in  stables  where 
animals  are  kept  and  fed,  and,  like  barnyard  manure, 
is  made  up  of  the  droppings  of  animals  and  the  bedding 
supplied  them.  In  some  stables  the  manure  is  allowed 
to  accumulate,  fresh  bedding  being  added  from  time 
to  time,  until  the  proper  season  to  apply  it  to  the  soil. 
The  stables  are  cleaned  out  occasionally  each  year, 
and  during  the  intervals  the  manure  accumulates  in 
the  stalls.  Manure  formed  in  this  way  has  a  high 
value;  being  kept  in  the  stable  it  is  protected  from 
the  leaching  of  rain,  and,  becoming  well  packed  by 
the  feet  of  the  animals,  is  protected  from  destructive 
fermentation  caused  by  bacteria.  The  value  of  stable 
manure  depends  in  a  large  measure  on  the  kind  and 
amount  of  bedding  used,  the  age  and  kind  of  animal, 
and  the  kinds  and  amount  of  food  supplied  them. 
Manure  from  young  animals  is,  as  a  rule,  less  valuable 
than  manure  from  maturer  animals.  As  the  liquid 
portion  of  manure  contains  most  of  the  nitrogen  it  is 
important  that  enough  bedding  be  used  to  absorb  and 
retain  it. 

When  stables  are  cleaned  at  short  intervals,  and  it 
is  found  necessary  to  keep  the  manure  some  time  before 
it  is  applied  to  the  soil,  some  measure  for  protecting  it 
from  the  action  of  the  weather  must  be  adopted  or  a 
loss  of  valuable  compounds  of  nitrogen  results.  When 
manure  is  thrown  out  it  quickly  becomes  hot,  and  a 
loss  of  ammonia  results.  Anyone  familiar  with  stables 
has  noticed  how  warm  a  manure  pile  may  become,  and 


Classification  of  manures  131 

that  a  smell  of  ammonia  is  often  noticeable.  This 
means  a  loss  of  much  valuable  nitrogen,  and  should, 
if  possible,  be  prevented. 

The  loss  of  ammonia  bom  manure  piles  is  caused 
by  the  aetion  of  a  certain  class  of  bacteria,  which  de- 
stroys the  organic  matter  of  manure,  forming  ammonia 
which  passes  off  as  a  gas.  If  the  manure  pile  be  pro- 
perly protected  the  ammonia  is  retained  and  changed 
into  nitrates.  The  beai  known  method  of  protecting 
manure  is  to  compost  it.  In  all  eaten  the  manure  pile 
should  be  under  a  shed  or  covering  of  some  sort  to 
protect  it  from  the  weather. 

126.  Composting. — The  decay  of  manure  i>  always 
caused  by  the  action  of  bacteria,  and  as  the  manure 
is  warmed  the  action  of  the  bacteria  becomes  more 
rapid.  If  the  manure  pile  be  thoroughly  moistened, 
nitrates  are  formed  by  the  bacteria  just  as  they  are 
formed  in  the  soil  when  nitrification  takes  place.  It, 
the  warm  pile  has  been  exposed  to  the  ran 
and  weather,  and  has  dried  out  no  nitrates  are  formed, 
but  in  their  place  compounds  of  ammonia  which  escape 
into  the  air.  An  unprotected  manure  pile  may  in  this 
way  become  in  a  short  time  of  almost  no  value.  The 
nitrates  which  are  formed  are  easily  soluble,  and  unless 
absorbed  in  some  way  are  rapidly  drained  away  from 
the  manure.  When  nitrates  are  formed  in  tin 
if  not  taken  up  by  plant  roots  they  are  partly  absorbed 
and  retained  by  the  soil  itself;  heme  the  practice  of 
mixing  ordinary  earth  with  manure  to  form  a  compost 
heap.  bed  1-  provided  fr<>m  which  no  drainage 

can  take  plaoe,  and  on  this  a  layer  of  manure. 


132  ELEMENTS    OF    AGRICULTURE 

The  manure  is  covered  with  a  layer  of  earth,  another 
layer  of  manure  placed  on  the  earth,  and  this  in  turn 
covered.  The  compost  heap  is  made  up  of  alternate 
layers  of  manure  -and  earth,  the  earth  layers  absorb- 
ing the  nitrogen  compounds  formed  in  the  manure. 
For  the  earth  may  be  substituted  plaster,  the  old  mor- 
tar from  buildings,  or  swamp  muck.  The  manure  may 
have  mixed  with  it  old  straw  or  hav,  dead  leaves  and 
any  other  refuse  matter  that  can  be  utilized.  Before 
applying  to  the  soil  the  compost  heap  should  be  thor- 
oughly worked  over  and  fermentation  allowed  to  start. 

Questions 

1.  What  is  a  manure?  2.  Into  what  two  classes  are 
manures  divided?  3.  Name  some  well-known  natural  ma- 
nures. 4.  What  is  marl?  5.  Why  are  marls  applied  to 
soils?  6.  What  is  gypsum,  and  why  is  it  used  for  a  ferti- 
lizer? 7.  Why  are  wood  ashes  valuable  as  a  fertilizer? 
8.  What  is  swamp  muck,  and  what  makes  it  valuable  as  a 
fertilizer?  9.  What  part  of  wood's  mold,  rotting  straw,  or 
dead  leaves  is  of  value  as  a  fertilizer?  10.  What  is  barn- 
yard manure?  11.  On  what  does  the  value  of  barnyard 
manure  mainly  depend?  12.  What  is  stable  manure? 
13.  Why  is  stable  manure  which  is  allowed  to  accumulate 
in  the  stable  of  more  value  than  that  which  is  thrown  out 
into  the  weather?  14.  What  causes  the  loss  of  ammonia 
from  manure  piles?  15.  How  may  the  loss  of  nitrogen  be 
prevented?  16.  Tell  how  a  compost  heap  is  made. 
17.  What  substances  besides  manure  may  be  used  in  form- 
ing a  compost  heap? 


.  (OOMMEIK  I  \  1.    I  i  i:  i  II .1/1  U  133 


GHAPTEB   WW— Commfk<  fai.  Fkrtili/ 

127.  Definition  of  Commercial  Fertilizers. — Artificial 
manuree;  or  commercial  fertilizer-,  are  Buch  sompounds 

iiiMiiut'acturcl  expreealj  for  oae  on  soils.  Phey 
may  be  divided  Into* three  elaaeee:  L  tfrntOGENOUS 
fertilizers,  including  such  compounds  u  ire  need  to 
supply  nitrogen.     2,   P<  >mpounda 

supplying  potaah.  3.  Phosphates,  compounds  sup- 
plying phosphorus. 

128.  Nitrogenous  Fertilizers. — Nitrogen  compound 
arc  the  in<»st  expensive  <»f  .ill  fertilizers,  and  as  nil: 

is  often  lacking  in  soils  these  fertilizers  are  of  the 
importance.    The  nitrogen  of  fertilizers  is  supplied  by 
a  number  of  dim-rent  compounda,  and  the  more  impor- 
tant of  these  will  now  be  briefly  described: 

1     Sodium   nitrate,  often  called  Chile  saltpetre,  is  a 

compound  of  nitrogen  with  sodium  and  oxygen,  con- 
taining  about  1<>  per  cent  of  nitrogen.  It  is  a  salt  and 
resembles  in  appea ranee  ordinary  table  salt  It  occurs 
naturally  in  greet  depoaita,  the  Deal  known  of  which 
an-  in  Chile;  hence  it>  name.     It   11  \ery  impure  when 

mined,  and  before  it  can  be  need  aa  i  fertilizer  must 

be  purified.     The  crude  -alt   i>  dieaolved  in  water  which 

li  afterwardi  i  i.  a/hen  the  purified  compounds 

t   in  the  form  of  small  crystals.     Nitr.r 
is  easily  soluble  in  water,  and  as  plants  take  up  their 

nitrogen  in  the  form  of  nitrafc  v  for  the 

use  of  plants  as  soon  as  dissolved  in  the  soil  wl 


134  ELEMENTS   OP  AGRICtTLTtTEE 

2.  Sulphate  of  ammonia  is  another  salt  containing* 
nitrogen,  and  is  used  to  some  extent  as  a  fertilizer.  It 
is  made  up  of  the  elements  nitrogen,  hydrogen,  sul- 
phur and  oxygen,  and  contains  about  20  per  cent  of 
nitrogen.  Sulphate  of  ammonia  is  produced  as  a  by- 
product by  gas  works  which  manufacture  illuminating 
gas  for  cities  and  towns.  It  is  easily  soluble  in  water, 
but  in  the  soil  must  be  changed  to  a  nitrate  before  it 
becomes  plant  food. 

Nitrate  of  soda  and  sulphate  of  ammonia  are  the 
only  salts  of  nitrogen  used  for  fertilizers.  A  large  part 
of  the  nitrogen  of  fertilizers  comes  from  organic  com- 
pounds, such  as  cottonseed-meal,  bones,  dried  blood, 
fish  scrap,  etc. 

3.  Cottonseed-meal  is  a  by-product  from  the  manu- 
facture of  oil  from  cottonseed,  and  is  now  produced  in 
immense  quantities.  In  the  oil  mills  the  cottonseed 
first  have  the  hulls — the  hard  outer  shell  from  which 
the  lint  grows — taken  off  by  machinery.  The  soft 
inner  portion  of  the  seed,  called  the  kernel,  is  then 
heated  in  immense  kettles,  after  which  process  it  is 
pressed  much  as  apples  are  pressed  for  cider,  only  the 
presses  are  much  more  powerful.  Most  of  the  oil  which 
the  seed  contains  is  pressed  out  by  this  process,  and 
the  remainder  of  the  kernels  formed  into  a  flat  cake 
which  from  the  great  pressure  is  as  hard  as  a  board. 
In  this  form  it  is  called  cottonseed-cake,  and  before 
it  can  be  used  must  be  ground  up  in  mills,  from  which 
it  comes  as  cottonseed-meal,  a  substance  of  a  rich, 
golden  yellow  color,  and  about  as  coarse  as  corn-meal. 

Great  quantities  of  cottonseed-meal    are    produced 


(  mm  Mi  i:<  i  m.   if  i:m  IZ1  135 

each  \ear  bj  the  oil  mills  of  the  South.  and  each 
more  of  it  is  being  used  for  a  fertilizer,  especially  in  the 
ootton  States.    Cottonseed-meal  contains  from  T  to  8 

per  cent  of  nitrogen,  and,  besides  this  valuable  plant 
food,  contains  1  to  2  per  cent  of  phosphoric  acid,  ami  1  S 
to  3  per  cent  of  potash.  When  applied  to  the  soil  it 
decays  rapidly,  and,  besides  the  plant  food  it  contains, 
it  supplies  the  soil  with  much  valuable  organic  matter 
which  goes  to  form  humus. 

!.  Bones  oi  animals  are  another  source  of  nitrogen 
for  fertilizers.  At  the  bone-yards  of  large  cities,  where 
great  number.-  of  dead  animal-  are  taken,  and  at  the 
slauirhter-hou>e>,  where  animals  are  prepared  for  mar- 
ket. iiiiMiMM  (jii.intitio  of  hone-  accumulate.  A  part 
of  the-«'  bonefl  i-  ground  up  and  sold  Bfl  a  fertilizer 
under  the  name  of  raw   r.ROUND  BONE.    The  raw  hone 

s  very  slowly,  and  requires  a  long  time  bed 
is  fit  for  plant  food.  Bom  i  are  often  steamed  or 
cooked  for  the  purpose  of  making  glne  or  oil,  and  the 
portion  remaining  after  this  process  is  sold  as  STEAMED 
It  decays  more  rapidly  in  the  soil,  and  is  of 
more  value  as  a  fertilizer.  Raw  ground  hour  contains 
2$  to  4£  per  cent  of  nitrogen,  steamed  bone   1 1 

ddes  nitrogen,  bones  contain  much  phos- 
phoric acid,  ami  are  classed  as  phosphatic  fertilizers. 

■  >.  Dried  bl I  \»  a  product  of  the  slaughter*!] 

when'  quantities  ofit  are  dried  and  sold  as  a  fertilizer. 

ilue  depends  on  its  nitrogen,  of  which  it  contains 
from   LO  t<»   1.'  pet  cent.      It  decay-  rapidly  in  th< 
and    makes  a    \aluahle   fertili.  I 

fankage  is  another    product    of    the    .-laughter- 


136  ELEMENTS    OF    AGRICULTURE 

house,  and  is  made  up  of  the  refuse  parts  of  the 
slaughtered  animals.  It  contains  from  10  to  12  per 
cent  of  nitrogen. 

7.  Fish  scrap  is  a  by-product  from  the  fish  canneries, 
where  large  quantities  of  fish  are  preserved  in  cans  for 
the  market.  The  refuse  parts  of  the  fish  are  dried  and 
sold  as  a  fertilizer.  It  contains  from  7  to  9  per  cent 
of  nitrogen. 

129.  Potash. — Until  about  forty  years  ago  all  the 
potash  of  fertilizers  was  supplied  by  wood  ashes,  stable 
manure,  and  waste  products,  such  as  rotting  straw  or 
tobacco  stems.  About  the  year  1860  there  were  found 
in  Germany,  near  the  town  of  Stassfurt,  great  deposits 
of  potash  salts,  which  were  probably  left  there  by  the 
evaporation  of  some  inland  sea  or  lake.  Great  quanti- 
ties of  these  potash  salts  are  now  mined  and  sold,  the 
Stassfurt  mines  supplying  potash  to  the  entire  world. 
The  potash  salts  as  found  An  the  mines  are  mixed  with 
various  other  compounds,  such  as  common  salt,  mag- 
nesium chlorides,  epsom  salts,  etc.  From  this  mixture 
pure  potash  salts  are  prepared. 

1.  Kainit  is  the  crude  salt  as  it  comes  from  the  mine 
and  contains  a  number  of  different  compounds.  Most 
of  the  potash  in  kainit  is  in  the  form  of  a  sulphate; 
that  is,  it  is  combined  with  sulphur  and  oxygen.  It 
contains  only  about  12  per  cent  of  potash. 

2.  Sylvinit  is  another  of  the  crude  salts,  and  most 
of  the  potash  it  contains  is  in  the  form  of  a  chloride. 
Sylvinit  contains  from  15  to  20  per  cent  of  potash. 

3.  Muriate  of  potash,  which  is  manufactured  from 
the  crude  salts,  such  as  kainit,  is  a  compound  of  potas- 


vi.   mi;  i  ii 


LSI 


tram  with  chlorine,  and  ii  Da  >re  propedj  called  p 
nun  chloride,    it  ii  <»n<'  of  the  beet  known  potassium 
fertiliaeia,  and  contains  aboul  50  per  cenl  oi  potaah.    . 
4.  Sulphate  ol  potaah  is  i  compound  of  potassium 

with    sulphur   and    oxygen,   and    i>    alao    manufact  un-d 

fmiii  the  crude  potaah  salta.     It  contains  about  the 

same  amount  of  potash  as  the  muriates,  and  is  much 
used  as  a  fVrh 

Questions 

• 
1.  What  are  commercial   fertilizers?     2.  Into  what  three 

classes  may  they  be  divided?  3.  What  two  inorganic  sub- 
stances supply  nitrogen  compounds  for  fertilizers?  4.  Why 
is  nitrate  of  soda  called  Chile  saltpetre?  5.  When  is  nitrate 
of  soda  suitable  for  plant  food?  6.  Tell  what  you  know 
about  sulphate  of  ammonia.  7.  How  is  cottonseed  -mm  I 
obtained  from  cottonseed?  8.  About  how  much  nitrogen 
does  cottonseed-meal  contain?  9.  With  what  other  valu- 
able compound  does  it  supply  the  soil?  10.  Name  four 
other  organic  substances  used  to  supply  nitrogen.  11 
what  country  do  most  potash  salts  come?  12.  Name 
two  of  the  crude  products,  and  tell  how  much  potash  each 
contains.  13.  What  is  muriate  of  potash,  and  how  much 
potash  does  It  contain?  14.  What  is  sulphate  of  potash, 
and  how  much  potash  does  it  contain? 


138  ELEMENTS    OF    AGRICULTUEE 


CHAPTER  XXVI.— Commercial  Fertilizers 
(Continued) 

130.  Phosphates. — The  phosphates  of  fertilizers 
comes  from  two  sources :  (1)  The  great  deposits  of  rock 
-phosphate;  (2)  The  bones  of  animals. 

131.  Where  Phosphates  are  Found. — Phosphate  rock 
is  found  in  many  parts  of  the  world.  In  Canada  there 
are  large  deposits  of  mineral  phosphates  called 
apatite.  In  the  United  States  great  quantities  of 
phosphates  are  found,  the  best  known  deposits  occur- 
ring in  the  States  of  North  Carolina,  South  Carolina, 
Florida  and  Tennessee.  In  the  United  States  the 
deposits  are  known  as  phosphate  rock. 

Phosphate  rock  varies  greatly  in  appearance  and 
composition,  and  occurs  sometimes  as  pebbles  in  bot- 
toms of  rivers,  sometimes  as  boulders  scattered 
through  the  soil,  and  again  as  great  beds  of  rock  re- 
sembling beds  of  limestone.  In  the  States  of  South 
Carolina,  Xorth  Carolina  and  Florida  the  deposits  of 
phosphates  are,  as  a  rule,  found  near  the  coast.  The 
so-called  river  rock  is  dredged  from  the  bottom  of 
rivers,  some  in  the  form  of  water-worn  stones,  and 
some  in  boulders  of  various  sizes,  which  are  taken  from 
the  mud  of  the  river  bottoms.  The  land  rock  occurs 
in  masses  varying  in  size  from  small  stones  to  boulders 
weighing  many  tons. 


VI.   KKKTIUZER9 


139 


132.  Appearance  of  Phosphate  Rock. — In  appear- 
ance phosphate  rock  varies  greatly.  The  soft,  white 
phosphates  of  Florida  resemble  marl,  end  are  nearly 
as  soft.  The  Tennessee  rock,  as  a  rule,  is  hard  and 
resembles  in  appearance  ordinary  limestone.  The  ordi- 
nary South  Carolina  rock  is  between  these  two  ex- 
tremes, being  of  a  dirty  gray  color  and  moderately 
hard. 

133.  Composition  of  Phosphate  Rock. — All  phos- 
phate rock,  wherever  it  occurs  and  whatever  its  appear* 
ance,  contains  some  compounds  of  phosphorus,  and  its 
value  as  a  fertilizer  depends  on  the  amount  and  condi- 
tion of  these  compound-.  bfosl  of  the  rock  used  for 
fertilizers  contains  phosphorUJ  combined  with  calcium 
and  oxygen,  which  compound  is  known  as  calcium 
phosphate  or  bone  phosphate.  Some  samples  of  phot* 
phate  rock  contain  as  much  as  98  per  cent  calcium 
phosphate,  and  some  rock  contains  almost  none  at  all. 
Good  rock  should  contain  at  least  50  per  cent  of  cal- 
cium phosphate  Tart  of  the  phosphorus  may  be 
hincd  with  iron  and  aluminum,  and  is  then  known  as 
iron  and  aluminum  phosphate  The  best  grades  oi 
contain  hut  little  iron  and  aluminum,  hut  in  some 
varieties  of  rock  all  the  phosphorUJ  is  comhined  with 
these  two  elements.  Such  rock,  while  of  some  value 
for  fertilizers,  is  not  nearly  so  valuable  as  the  calcium 

phosphate  rook. 

:<les  compounds  of  phosphorus,  phosphajte  rook 

contains  rarying  quantities  of  sand,  organic  m 
iron  and  sulphur,  and  minute  quantities  of  several  other 


140  ELEMENTS    OF   AGRICULTURE 

134.  Manufacture  of  Commercial  Phosphates. — The 
phosphorus  compounds  in  phosphate  rock  are  practi- 
cally insoluble  in  water,  and  before  they  can  become 
plant  food  must  be  changed  into  soluble  compounds. 
Where  phosphate  rock  is  applied  to  soils  the  weak  acids 
in  the  soil  gradually  change  the  insoluble  phosphates 
into  soluble  compounds,  but  the  change  is  slow  at  best. 
Now,  strong  mineral  acids,  such  as  sulphuric  acid — 
oil  of  vitrol — have  the  same  effect  as  the  weak  soil  acids 
on  the  insoluble  phosphates,  changing  them  into  soluble 
compounds,  and  the  stronger  the  acid  the  more  rapid 
the  change.  This  fact  is  taken  advantage  of  in  the 
manufacture  of  phosphates,  and  the  process  is  briefly 
as  follows :  The  phosphate  rock,  after  being  cleaned,  is 
ground  to  a  fine  powder  in  powerful  mills,  and  this 
powder  mixed  with  strong  sulphuric  acid.  When  the 
acid  is  mixed  with  the  dry  powder  it  first  forms  a  sticky 
mass  like  stiff  mud;  this  is  thoroughly  worked  up  and 
allowed  to  stand  in  order  to  give  the  acid  time  to 
change  all  the  insoluble  compounds  into  soluble.  The 
sulphuric  acid  in  changing  the  phosphate  compounds 
is  itself  changed  into  calcium  sulphate,  or  gypsum.  The 
change  in  the  sulphuric  acid  is  necessary,  for  the  acid 
itself  destroys  all  vegetation,  and  any  unchanged  acid 
would  ruin  the  fertilizer.  The  amount  of  acid  neces- 
sary to  form  the  soluble  phosphates  is  carefully  deter- 
mined beforehand,  and  the  right  amount  added.  After 
the  mixture  has  stood  the  proper  length  of  time  it 
becomes  about  as  dry  as  ordinary  soil,  and  all  the  acid 
is  neutralized,  i.  e.,  changed  into  sulphate.    The  phos- 


COM  Ml   i:<    !  \1.    II  Kill  l/l   KS 


111 


phatc  is  now  placed  in  sacks  and  sold  as  acid  PHOS- 
PHATE,  DISSOLVED  BONK,  DISSOLVED  ROCK,  etc. 

There  ire  three  kindi  <>f  phosphorus  compounds  in 
acid  phosphate,  and  they  ere  known  as:  (1)  Soluble 
PHOSPHORIC    M  id, '  which   is  easily   Boluble   in    water; 

(2)     REVERTKI)     PHOSPHORIC     ACID,     which     is     ea-ilv 

soluble  in  weak  acids,  such  as  are  found  in  the  BOilj 
i"»)  iN'Mii  i  r.i.i;  PHOSPHORIC  acti>.  which  is  soluble  in 
strong  acids.  The  insoluble  phosphoric  acid  is  part 
of  the  original  ground  rock  which  has  not  hi 
on  by  acids;  it  forms  hut  a  very  small  part  of  good 
fertilizers,  seldom  above  1  per  cent.  The  soluble  and 
reverted  phosphoric  acids  are  classed  together  as  avail- 
able phosphoric  acid.  The  sum  of  the  available  and 
insoluble  gives  what  is  called  the  total  phosphoric 

AC  ID. 

135.  Bone  Phosphate. — The  horns  of  all  animals 
contain  large  amounts  of  phosphate  of  linn-,  and  are 
much  used  for  fertilisers.  When  the  hones  are  simply 
ground  and  sold  for  a  fertilizer  the  product  U  known 
as  raw  bone,  and  nearly  all  of  the  phosphoric!  acid  it 
contains  is  insoluhle.  The  steamed  hone,  while  it  is 
made  up  principally  of  insoluhle  phosphoric  acid,  de- 
much  more  rapidly  in  the  soil,  and  for  this  p 
is  of  more  value  as  a  fertilize  r  fi\|  a  large  pari  of  the 
Organic    matter   has    been    r  by    the    : 

cooking,  steamed   hour  contain-   more   phosplmri. 
than   raw  hone.      Raw  bone  <ontam- 

of  phosphoric  sold,  :>i  per  cent  of  bone  phos- 

phate.   Steamed  b  at  of 

phosphoric  acid,  or  48  to  63  per  cent  of  bone  phosphate. 


142  .        ELEMENTS    OF   AGRICULTURE 

136.  Valuation  of  Fertilizers. — Commercial  fertili- 
zers are  v  allied  according  to  the  amounts  of  nitrogen, 
phosphoric  acid  and  potash  they  contain,  and,  in  order 
to  protect  the  consumer  from  dishonest  manufacturers, 
most  States  have  employed  chemists  whose  business  it 
is  to  examine  all  fertilizers  sold  in  their  State,  to  see 
if  they  contain  what  the  manufacturers  claim  for  them. 
Each  package  of  fertilizer  sold  must  have  printed  on 
it  the  amounts  of  nitrogen,  phosphoric  acid,  and  potash 
it  contains,  so  that  buyers  may  know  what  they  are 
getting.  Each  State  chemist  fixes  a  value  per  pound 
for  nitrogen,  phosphoric  acid  and  potash,  and  with 
them  anyone  may  calculate  the  value  of  any  commer- 
cial fertilizer.  Suppose,  for  instance,  that  nitrogen 
is  valued  at  15  cents  a  pound;  then  if  a  fertilizer  con- 
tains 2  per  cent  of  nitrogen  its  supply  is  worth  $6.00 
per  ton.  If  the  fertilizer  contains  also  8  per  cent  of 
available  phosphoric  acid  which  is  valued  at  4  cents 
a  pound,  its  supply  of  phosphate  is  worth  $6.40  per 
ton.  If,  besides  nitrogen  and  phosphoric  acid,  the  fer- 
tilizer contains  1  per  cent  of  potash  valued  at  5  cents 
a  pound,  its  potash  is  worth  $1.00  per  ton,  making  a  ton 
of  the  fertilizer  worth  $13.40. 

Nitrogen,  2%  of  2,000  lbs.  =  40  lbs.  at   15tf  per  lb.  =  $6  00 
Phosphoric  acid,  8%  of  2,000  lbs.  =  160  lbs.  at  4tf  per 

lb.=  6  40 

Potash,  1%  of  2,000  lbs.  =20  lbs.  at  5tf  per  lb.  =  1  00 


$13  40 


The  valuations  placed  on  nitrogen,  phosphoric  acid 
and  potash  by  official   chemists   are   based   upon   the 


COMMEHClAL    MMIIIZEKS  143 

wholesale  prices  of  these  substances  at  points  of  supply. 
For  in.-tance.  if  nit  nit.-  of  >oda  >»-Il>  for  |48  a  ton,  and 
contains  1G  per  cent  of  nitrogen,  then  it >  nitrogen  ii 
worth  l."»  cents  a  pound.     If  cottonseed-meal  sel 
$18  a  ton,  and  contains  G.75  per  cent  of  ni tropin,  then 
it.-  nitrogen  u  worth  13.8  centi  a  pound.    In  tin-  same 
way,  \alue-  arc  fixed  f<>r  the  phosphoric  acid  and  potash 
supplied    by    various    substances.  •    These    valin  - 
usually  fixed  once  each  season,  and  remain  unci).! 
until  tin-  DOXi  sea.-on. 

When  the  various  substances  supplying  nitrogen, 
phosphoric  acid  and  potash  are  mixed  to  form  a  com- 
plete fertilizer — that  is,  a  fertiliser  containing  all  of 
these  plant  foods — the  valuation-  of  the  official  ehem- 
ists  inav  1«'  used    to   estimate    the  the   raw 

material.-,  SI  in  the  example  already  given.  The  Belling 
of  the  fertilizer  is,  however,  often  greater  than 
the  estimated  value  of  the  raw  materials,  because  the 
manufacturer  charges  enough  to  insure  himself  a  profit 
after  paying  the  cost  of  manufacturing  and  of  placing 

the  fertilizer  on  the  mark> 

her  the  valuation  of  the  official  chemist  nor  the 
market  price  indicate-,  however,  the  agricultural  value 
of  any  fertilizer,  for  its  agricultural  value  can  he  d 

mined  only  by  actual  testa  in  the  field.    The  published 

analyses  and  the  official   valuations   of   fertilizer- 
bowereTj  of  benefit   to  the  farmer  in  several  ways. 

They  -how,  !ir-t.  what  the  composition  of  a  fertilizer 
is,  and  whether  it  fulfills  the  claims  of  the  manufac- 
turer. Next,  by  showing  the  farmer  how  to  caleulato 
for  himself  the  market  value  of  the  guaranteed  con- 


144 


ELEMENTS    OF    AGRICULTURE 


stituents  of  a  fertilizer,  they  enable  him  to  tell  whether 
the  manufacturer  is  charging  to'o  much  for  his  article, 
and  what  are  the  relative  values  of  different  brands  of 
fertilizers.  And,  finally,  they  warn  the  farmer  that 
there  is  very  little  in  a  name  or  brand,  for  in  not  a  few 
instances  manufacturers  have  been  known  to  sell  the 
same  article  under  many  different  names  or  brands. 

Questions 

1.  From  what  two  sources  are  the  phosphates  of  ferti- 
lizers derived?  2.  Name  the  States  in  which  the  best 
known  deposits  of  phosphate  rock  are  found.  3.  What  is 
the  difference  between  land  rock  and  river  rock?  4.  How 
does  the  land  rock  usually  occur  in  the  soil?  5.  How  does 
the  phosphate  rock  from  different  localities  differ  in  ap- 
pearance? 6.  All  phosphate  rock  contains  compounds  of 
what  element?  7.  With  what  two  elements  is  the  phos- 
phorus of  phosphate  rock  usually  combined  and  what  is  the 
compound  called?  8.  On  what  does  the  value  of  phosphate 
rock  principally  depend?  9.  About  how  much  calcium 
phosphate  should  good  rock  contain?  10.  With  what  other 
elements  is  a  part  of  the  phosphorus  combined?  11.  How 
are  the  insoluble  phosphates  changed  into  soluble  com- 
pounds in  the  soil?  12.  Describe  the  process  of  manufac- 
turing soluble  phosphates.  13.  What  becomes  of  the  sulphu- 
ric acid  used  to  make  soluble  phosphates?  14.  What  are  the 
soluble  phosphates  called?  15.  What  is  meant  by  soluble 
phosphoric  acid,  what  by  available,  and  what  by  total? 
16.  What  is  the  difference  between  raw  bone  and  steamed 
bone?  17.  About  how  much  calcium  phosphate  does  each 
contain?    18.  How  are  fertilizers  valued? 

PROBLEM 

Calculate  the  value  of  a  ton  of  fertilizer  containing  3  per 
cent  nitrogen,  9  per  cent  available  phosphoric  acid,  and  2 
per  cent  potash;  nitrogen  being  valued  at  14  cents  a  pound, 
phosphoric  acid  at  4  cents,  and  potash  at  5  cents. 


USE    OF    MANURES  145 


CHAPTER  XXVII .^Use  of  Manures 

137.  Purpose  of  Manures. — The  purpose  of  applying 
manures  is  always  to  increase  the  yield  of  cultivated 
crops.  The  manures  may  be  applied  to  furnish  food 
for  some  one  particular  crop,  or  they  may  be  Oft 
increase  the  fertility  of  the  soil,  but  in  each  ease  the 
object  is  the  same.  Manures  that  are  used  to  furnish 
plant  food  for  some  one  particular  crop  are  called 
sii(  ial  manures.  Manures  that  are  used  to  improve 
the  condition  of  the  soil  are  called  general  manures. 
For  special  manures  only  such  emu  pounds  as  furnish 
easily  available  plant  food  are  need.  Pot  general 
manures  rabetances  ere  need  which  increase  the 

of  plant  food  in  the  soil,  either  by  being  gradually 
changed  into  plant   food  themselves,  or  by  forming 

available  compounds  with  the  unavailable  plant  food 
already  in  the  <i»il.  The  process  of  increasing  the  fer- 
tility of  worn  soils  is  called  sou.  restoration. 

138.  Restoration  of  Worn  Soils. — A  worn  soil  is  one 
that  for  i  .11  fails  to  produce  profitable  crope. 
Thii  failure  to  produce  crops  may  arise  from  poor  culti- 
vation, or  it  may  be  that  one  or  all  of  the  different 
compounds  supplying  available  plant  food  are  lacking; 
but  whatever  the  cause,  the  trouble  should  be  known 
before  a  cure  is  attempted  The  successful  physician 
always  learns,  if  possible,  the  nature  of  his  patients 
illness  before  attempting  a  cure,  and  so  should  those 

10 


146  ELEMENTS    OF    AGRICULTURE 

who  expect  to  cure  sick  soils  know  the  cause  of  the 
trouble  before  applying  remedies. 

There  are  many  ways  in  which  a  soil  may  become 
poor,  but,  as  already  pointed  out,  the  loss  of  moisture 
and  organic  matter  is  the  chief  cause  of  poor  soils. 
Therefore,  in  improving  a  poor  soil,  the  first  point  to 
be  inquired  into  should  be  its  supply  of  water  and 
organic  matter.  A  soil  well  supplied  with  organic 
•  matter  is,  if  well  cultivated,  usually  well  supplied  with 
water  and  plant  food;  so  it  is  safe  to  begin  the 
improvement  of  worn  soils  by  looking  to  the  supply  of 
organic  matter.  Increase  the  soil's  supply  of  organic 
matter,  and  you  increase  its  supply  of  moisture  and 
plant  food.  The  usual  method  of  increasing  the  soil's 
store  of  organic  matter  is  to  grow  some  crop  and  plow 
it  under  while  it  is  growing.  Leguminous  crops,  such 
as  clover  and  beans,  are  the  best  for  the  purpose,  as 
they  gather  from  the  air  stores  of  nitrogen  which, 
when  they  decay,  are  added  to  the  store  in  the  soil. 
The  plowing  under  of  growing  crops  is  called  green 
manuring,  and  is  much  practiced  on  worn  soils.  The 
green  crops,  decaying  in  the  soil,  form  valuable  com- 
pounds of  nitrogen  and  humus.  The  humus  increases 
the  soil's  power  to  hold  water,  and  combining  with 
the  insoluble  phosphates  and  potash  compounds  in  the 
soil  forms  available  plant  foods.  As  the  organic  matter 
of  tjie  green  manure  decays  slowly,  and  the  humus 
which  is  formed  acts  slowly  on  the  insoluble  com- 
pounds, the  good  effects  of  one  application  of  green 
manure  may  last  throughout  several  years.  For  green 
manuring  there  is  no  better  crop  than  the  old-field  pea, 


USE    OF    MANURK8  147 

or  cowpea.  It  will  grow  in  a  very  poor  soil  and  add 
greatly  to  its  store  of  nitron 

The  addition  to  the  soil  of  stable  manure  accom- 
plices tin-  same  purpoee  ns  plowing  under  green  crops; 
■!  it  does  more,  for  it  addl  to  the  soil  some  useful 
compounds  of  phosphorus  and  DOttsfa  and  a  host  of 
ireful  bacteria.  Stable  manure  is  both  a  special  and 
general  manure;  it  adds  to  the  soil  compounds  that 
■00H  become  available  for  plant  food,  and  also  grad- 
ually improves  the  condition  of  the  soil.  Stable  manure 
is  probably  the  most  valuable  of  all  manures,  and  may 
be  used  to  great  advantage  on  most  soils.  It  should 
udeel  u  om>  of  the  most  valuable  products  of  the 
farm,  and  should  never  be  wasted. 

Organic  matter  and  moisture,  however,  are  not  the 

only  plant  foods  that  may  be  lacking  in  poor  soils;  some 

Of  more  of  the  mineral  elements  may  be  wanting. 

Thus  there  are  soils  in  which  the  supply  of  lime  has 

become  exhausted,  ami  where  this  is  the  ease  the  soil, 

from  the  accumulation  of  humus  acids,  usually  becomes 
sour.  This  acidity  may  !»«■  corrected  by  the  application 
of  lime.  Soils  rich  in  decaying  organic  matter  are  often 
unproved  by  an  application  of  lime. 

The  total  supply  of  phosphoric  acid  and  potash  in 
soils  is  seldom  exhausted,  though  such  eases  do  occur. 
The  available  phosphoric  acid  and  potash,  on  the  other 
hand.  d  exhausted,  and  must  be  renewed  either 

by  the  application  of  a  fertilizer,  or  by  treating  the  soil 
so  as  to  render  the  insoluble  compounds  available. 

When  a  soil  becomes  worn  and  poor  it  should  be 
carefully  examined,  and,  if  possible,  the  cause  of  the 


148  ELEMENTS    OF   AGRICULTURE 

trouble  ascertained;  then  the  proper  course  of  treat- 
ment may  be  determined  on.  It  is  no  simple  matter 
to  restore  the  fertility  of  a  worn  soil,  and  there  are  no 
fixed  rules  to  be  followed;  each  individual  case  must 
be  carefully  studied  and  treated.  Very  often  the  proper 
treatment  can  be  determined  only  by  experiment. 

139.  Special  Manuring. — In  using  special  manures 
the  manure  is  added  for  the  benefit  of  some  one  par- 
ticular crop,  and  it  is  of  more  importance  to  know  the 
needs  of  the  crop  in  question  than  it  is  to  know  the 
needs  of  the  soil.  For  instance,  clover  and  cowpeas  are 
crops  which  require  large  amounts  of  nitrogen  com- 
pounds for  their  production,  but  which  are  able  to  draw 
on  the  atmosphere  for  a  large  part  of  their  needs.  It  is 
therefore  useless  to  supply  such  crops  with  nitrogenous 
manures.  The  soil  may  be  very  poor  in  nitrogen,  but 
that  is  of  little  consequence  so  far  as  these  crops  are 
concerned;  they  are  to  a  certain  extent  independent  of 
the  soil  for  their  nitrogen  supply.  Again,  1,000  pounds 
of  tobacco  leaves  require  for  their  production  40 
pounds  of  potash  and  only  3.4  pounds  of  phosphoric 
acid.  It  is  evident  that  tobacco  requires  for  its  pro- 
duction more  potas"h  than  phosphoric  acid,  and  we  may 
use  this  knowledge  in  preparing  a  fertilizer  for  use  on 
this  crop. 

When  manures  are  applied  to  increase  the  yield  of  any 
particular  crop,  it  is  the  crop  that  is  to  be  fed,  and  not 
the  soil.  By  analyzing  the  crop  in  question  we  may  learn 
the  amounts  of  plant  food  it  requires  for  its  produc- 
tion. Now,  it  would  seem  an  easy  matter  to  analyze 
the  soil  and  find  out  what  it  lacks  in  the  way  of  plant 


U8JC    OF    MANURES 

food,  and  with  this  information  and  the  knowleage  of 
what  the  crop  in  question  requires,  apply  the  proper 
amounts  of  the  fertilizers.  The  difficulty  in  the  way 
is,  thjit  while  it  is  possible  to  determine  with  consider- 
able aeeur.-iev  how  much  nitrogen,  phosphoric  acid, 
potash,  lime,  etc.,  I  soil  contains,  there  is  no  accurate 
method  for  determining  just  how  much  of  each  of  these 
substances  is  in  available  form  for  plant  food.  We 
may  find  by  analysis  that  a  soil  contains  .5  per  cent 
of  potash,  hut  for  all  we  know  from  the  analysis,  the 
total  amount  may  he  unavailahle  for  plants.  On  the 
other  hand,  we  do  know  from  accurate  analyses  just 
how  much  plant  food  is  required  to  produce  any  single 
crop,  and  can  use  the  knowledge  to  advantage  in  apply- 
ing fertilizers. 

l.ut  ditTerent  plants  vary  greatly  in  their  power  of 
procuring  their  food  supplies  from  the  soil;  one,  for 
example,  requiring  large  amounts  of  potash  may  be 
able  to  obtain  its  supply  of  this  constituent  much  more 
easily  and  readily  than  another  requiring  a  smaller 
amount  of  it.    In  such  cases  analysis  is  not  a  safe  guide. 

No  fixed  rules  can  be  laid  down  for  the  use  of 
manures;  different  crops  require  very  different  treat- 
ment, and  even  the  same  crop  under  varying  conditions 
of  soil  and  climate  takes  up  varying  amounts  of  plant 
food.  The  only  reliable  way  of  determining  what  dif- 
t  crops  require  in  the  way  of  plant  food  is  by 
experiment.  Kvery  farmer  must  determine  for  himself 
the  kind  and  amount  of  fertilizer  his  crops  require,  and 
in  doing  this  he  may  be  greatly  aided  by  a  knowledge 
of  the  composition  and  habits  of  growth  of  the  crops. 


150  ELEMENTS    OF   AGRICULTURE 

Questions 

1.  What  is  the  object  in  applying  manures  to  soils? 
2.  What  is  meant  by  a  general  manure?  3.  To  what  kind  of 
soils  are  general  manures  usually  applied?  4.  When  is  a 
soil  said  to  be  worn?  5.  In  restoring  a  worn  soil  what  is 
the  first  thing  to  be  considered?  6.  Name  two  of  the  chief 
causes  of  poor  soils.  7.  What  is  the  usual  method  of  in- 
creasing the  organic  matter  in  the  soil?  8.  What  is  the 
process  called?  9.  How  does  the  plowing  under  of  a  green 
crop  improve  a  poor  soil?  10.  Why  is  stable  manure  of 
benefit  to  poor  soils?  11.  What  are  the  best  crops  to  use  for 
green  manure?  12.  What  effect  does  the  loss  of  lime  have 
on  the  soil?  13.  How  may  acid  soil  be  improved?  14.  What 
is  meant  by  a  special  manure?  15.  Special  manures  should 
contain  the  plant  food  in  what  form?  16.  How  does  a 
knowledge  of  the  composition  of  crops  aid  in  determining 
the  application  of  special  manures?  17.  Why  can  you  not 
lay  down  fixed  rules  for  the  application  of  manures? 


M.l  D    i  l-STINQ**  151 


PART  V.— Farm  Crops 

CHAPTEB  x.wili.    Seed  Testing 

140.  Primary  Object  of  Agriculture. — Professor  S. 
ihnson,  one  of  our  foremost   writers  on  agricul- 
tural subjects,  thus  defines  the  object  <>f  agriculture: 
*  The  object  of  agriculture  i>  the  production  <>f  certain 

plants  and  certain  animals  which  arc  employed  to 
clothe  and  otherwise  serve  the  human   race.     The  first 
aim,  in  al  -  tin-  production  of  plants."*     The 

successful  fanner  should  then  strive  to  produce,  at  t lie 
smallest    possible  coat,   the  largest  crops  of  certain 

plants.     In  order  to  produce  the  largest  crops  he  must 

know  something  of  the  habits  ami  needs  of  the  plants 

in  question.  It  would  he  unwise  to  attempt  to  grow 
rice  or  cotton  in  Maine,  or  ragar  beets  in  Florida;  nor 

would   it   be  advisable  t<>  attempt    to  grow  celery   in   a 

dry,  sandy  soil,  or  sweet  potatoes  in  a  cool,  damp 
Each  plant  ha-  it-  preference  in  regard  to  soil  and 

climate,  and  each   requires   for  its  proper  growth  and 

•  pment   certain   kind-  of  plant    food.      The   study 

of  agriculture  among  other  things  endeavors  to  find  out 

the  various  requirements  of  different  farm  crops,  and 
to  make  rules  for  their  cultivation  which,  if  properly 
observed,  will  produce  the  largest  possible  crop  at  the 
least  <«>-t. 

•How  Crops  Grow,  by  8.  W.  Johnson,  page  L. 


152 


ELEMENTS    OF    AGRICULTURE 


141.  General   Farming   and   Special   Farming. — Od 

many  farms  are  produced  each  year  several  different 
kinds  of  crops;  such  as  wheat,  corn,  tobacco,  and  oats. 
This  practice  is  called  general  farming.  But  gradu- 
ally the  production  of  one  main  crop  on  each  farm  is 
becoming  customary.  In  addition  to  such  crops  as  are 
needed  to  feed  themselves  and  their  stock,  many  plantT 
ers  raise  for  the  market  only  one  main  crop,  as  for  ex- 
ample, cotton,  rice,  or  tobacco.  This  is  called  special 
farming.  The  kind- of  crops  the  farmer  raises  is  usually 
determined  by  his  soil  and  climate,  and  by  the  demands 
of  the  market. 

142.  Selecting  Seed. — After  determining  on  the 
kind  of  crop  to  be  planted,  and  after  preparing  the 
soil  in  which  to  plant  it,  the  next  important  step  is 
selecting  the  seed;  and  in  doing  this  it  is  important 
to  remember  that  poor  seed  produce  poor  crops.  Select 
only  good,  pure  seed  for  planting.  Seed  are  unfit  for 
planting:  (1)  When  they  come  from  diseased  or  ill- 
shaped  plants,  (2)  when  they  are  not  fully  matured, 
(3)  when  they  are  too  old,  (4)  when  they  have  been 
attacked  by  disease  or  insects,  (5)  when  they  are  small 
and  ill-shaped,  (6)  when  they  are  mixed  with  other 
seed  or  trash. 

143.  How  to  Test  the  Purity  of  Seed.— The  first 
thing  to  do  is  to  weigh  the  seed.  The  seed  of  different 
crops  vary  in  weight,  and  the  weights  per  bushel  for 
pure  seed  have  been  determined  for  most  farm  crops. 
These  standard  weights  are  given  in  a  table  in  the 
appendix.  If  the  sample  of  seed  to  be  tested  does  not 
agree  in  weight  with  the  standard,  then  it  is  reason- 


SEED  TESTING  153 

able  to  suppose  that  something  ii  vreng,  and  further 
test  should  be  made.  Whatever  the  weight  of  tin*  seed, 
it  i>  well  to  take  I  small  amount,  >ay  an  OOJU e,  exam- 
ine  it  earefully  and  pick  out  all  the  tra>h.  unsound 
and  foreign  seed.  Foreign  seed  mean  any  seed 
other  than  the  kind  called  for  by  the  sample.  B] 
weighing  the  impurities  the  per  cent  of  pure  seed  may 
he  determined. 

144.  Germinating:   Tests   for   Seed. — Tin    most    im- 
portant test  for  seed  is  determining  their  power  to 
minate,  thai  is,  their  power  to  grow  when  planted.    The 
seed  may  be  apparently  sound  and  contain  almost   no 
trash  or  impure  seed,  and  yet  fail  to  grow  when  planted 
Old  seed  often  fail  to  grow.    A  simple  method  of  germi- 
nating seed  was  described  in  the  experiment  on  pegs 
36,  and    it    M   well   to   tot   all   seed   in    this   way    before 
planting.    Take  say  50,  100,  or  200  seed,  depend  i: 
their  site,  and  germinate  them  *|  described  in  t 
penmen  t.     B)   being  eareful  to  liave  all  the  conditions 
of  temperature  and  moisture  ju>t   right,  and  by  noting 

the  nnmbex  Bpronting,  the  per  cent  of  lonnd  seed  may 

be  determined. 

145.  Necessity  for  Testing  Seed. — It  is  unfortu- 
nately true  that  many  kinds  of  seed  are  adult* a 
some  by  aeeident,  other-  by  design.  Small  seed,  such 
as  grass  or  clover  seed,  are  easily  adulterated,  ami  the 
impurities  are  difficult  to  detect.  The  U.  S.  Depart- 
ment of  Agriculture  at  Washington  has  made  trials 
of  many  kinds  of  seed,  and  Fig.  H  shows  the 

of  a  test  of  red  clover  seed.     Only  46.2  per  cent  of 
the  seed  bought  could   be   relied  on  to  grow   when 


154 


ELEMENTS    OF    AGRICULTURE 


planted.  "  More  than  one-half  of  the  total  was  waste, 
or  worse,  making  the  actual  cost  of  the  good  seed  more 
than  double  the  amount  supposedly  paid  for  it."*  The 
market  price  of  the  seed  was  $3.50  per  bushel,  but  as 
more  than  half,  53.8  per  cent,  of  this  amount  was 
waste,  the  good  seed  actually  cost  $7.5G  per  bushel. 
Many  examples  of  this  kind  might  be  given  to  show 
the  necessity  for  seed  testing.     Of  course  all  the  -seed 

sold  on  the  market  are  not 
so  bad  as  the  sample  used 
in  this  test.  Some  lots  of 
seed  are  very  good,  and  con- 
tain almost  no  impurities. 
On  the  other  hand,  there 
are  other  lots  of  seed  much 
worse  than  the  one  cited. 
For  example,  the  U.  S.  De- 
partment of  Agriculture 
found  one  sample  of  clover 

Fig.  22— Red  clover  (Trifolium 

r>raLen*e):l,  one  pound  of  seed Las  seed  that    Contained  Only  .8 

bought;   2.  pure  seed;    3,  broken  "  J 

seed  and  dirt;  4,  spurious    seed;  f     *  frormiTinhlp 

6,  total  waste;  6,  pure  and  germi-  per  cent  oi  pure,  germmaDie 

nable  seed     (From  Farmers' Bui-  .        •—  ■.     ,  o 

letin,  No.  in,  u.  s.  Dept.  Agr.)  seed.  The  market  price  ot 
this  seed  was  $5.75  per  bushel,  but  the  actual  price  for 
the  good  seed  was  at  the  rate  of  $703.80  per  bushel. 

146.  Deterioration  of  Seed. — Good  seed  as  a  rule 
produce  good  crops,  which,  in  turn,  produce  good  seed. 
But  this  is  true  only  when  the  crop  is  grown  under 
favorable  conditions.  Poorly  cultivated  crops  pro- 
duce a  poorer  quality  of  seed  than  those  from  which 


•Farmers'  Bulletin  No.  Ill,  U.  S.  Dept.  Agr.,  1900. 


SKI-. li     I  I  MINO  155 

they  grow,  and  the  quality  is  said  to  deteriorate.  Seed 
from  crops  grown  in  a  cold  climate  when  planted  in  a 
warm  climate  often  produce  an  improved  quality  of 
seed.  On  the  other  hand,  seed  taken  from  I  warm 
climate  to  a  cold  often  produce  an  inferior  quality 
BcL  Good  seed  deteriorate  \vh  n  planted  in  un- 
suitable soils,  or  in  soils  not  well  supplied  with  the 
proper  plant  foods.  All  farms  crops  originally  grew 
wild.     Man    found    them    useful    and    cultivated    them. 

By  great  cure  in  selecting  ind  planting  only  tlx-  best 
seed  and  by  thorough  cultivation,  the  quality  has  been 
steadily  improved  and  is  still  being  improved.  But  it 
is  only  by  constant  attention  that  they  ire  kepi  up  to 
their  improved  condition.  If  neglected  they  soon  be- 
come as  poor  as  they  were  originally. 

EXPERIMENT 

Purchase  an  ounce  of  gran  or  clover  seed  from  some  dealer.  With 
the  class,  pick  oner  the  seed  carefully,  separating  the  good,  sound  seed 
from  the  trash  and  foreign  seed.  Weigh  the  sample  and  determine 
tfie  per  cent  of  sound  teed.  Sprout  100  of  the  sound  seed  and  note 
the  number  germinating. 

Questions 

1.  What  Is  the  primary  object  of  agriculture?  2.  Why  is 
it  advisable  to  know  something  of  the  habits  of  the  plants 
grown  for  use  on  the  farm?  3.  What  Is  general  farming? 
4.  What  is  special  farming?  5.  After  preparing  the  soil 
and  determining  on  the  kind  of  crop,  what  is  the  next  step? 
6.  In  selecting  seed,  what  are  some  of  the  points  to  be  con- 
sidered? 7.  How  may  seed  be  tested  for  purity?  8.  How 
may  the  germinating  power  of  seed  be  tested?    9.  What 


156  ELEMENTS    OF    AGEICULTUKE 

was  the  result  of  the  test  of  red  clover  seed  by  the  United 
States  Department  of  Agriculture?  10.  What  is  meant  by 
the  deterioration  of  seed?  11.  What  are  some  of  the  causes 
of  the  deterioration  of  seed? 

PROBLEM 

Suppose  we  buy  10  pounds  of  seed  at  14  cents  a  pound. 
After  testing  we  find  that  the  lot  contains  only  46  per  cent 
of  seed  that  will  grow.  What  is  the  cost  of  the  good  seed 
a  pound? 


CEREAL  AND  FODDER  CEOP8  157 


CHAPTIi;  X XIX. —Classification  of  Crops: 
Cereal  and  Fodder  Crops 

147.  Classification. — There  are  so  many  kinds  of 
crops  grown  on  the  different  farms  of  this  country 
that  to  attempt  to  describe  each  one  separately  would 
require  too  much  space  and  time.  Fortunately  for  our 
purpOM  many  of  these  crops  are  alike  in  their  manner 
of  cultivation  and  growth,  and  we  may  arrange  the 
more  important  farm  crops  into  a  few  classes. 

The  grain  crops,  Indian  corn,  wheat,  oats,  rye,  bar- 
ley, etc.,  are  all  placed  in  one  class  and  called  cerkal 
CSOP&  Cropi  grown  f<»r  hay,  fodder,  or  pasture  are 
all  called  forage  crops.  Crops  grown  for  their  roots 
or  tubers,  such  as  potatoes,  turnips,  beets,  etc.,  are 
called  root  and  TUBER  crops;  and  the  crops  not  in- 
clined in  any  of  these  classes  are  described  as  mis- 
cellaneous crois.     We  have  then: 

1.  Cereal  or  Grain  Crops:  Indian  corn,  wheat,  oats, 
rye,  barley,  rice,  etc. 

2.  Forage  Crops:  clovers  and  grasses  for  hay,  fod- 
der, and  pasturr. 

3.  Root  and  Tuber  Crops:  beets,  turnips,  potatoes, 
etc. 

4.  Miscellaneous  Crops :  tobacco,  cotton,  fruit  crops, 
garden  crops,  etc. 

148.  Cereals. — Tin-  three  important  cereal  crops  of 
this  country  are  Indian  corn,  wheat,  and  oats.    Rice 


158  ELEMENTS    OF    AGRICULTUBE 

is  also  an  important  grain  crop,  but  its  growth  is  lim- 
ited to  a  small  section  of  country.  By  the  word  corn 
in  the  United  States  is  meant  Indian  corn  or  maize. 
In  many  foreign  countries  the  word  corn  means  the 
seed  of  all  cereal  plants — wheat,  rye,  oats,  barley,  and 
Indian  corn.  The  word  corn' as  we  shall  use  it  always 
refers  to  Indian  corn. 

The  cereal  crops  are  grown  for  the  seed  they  pro- 
duce. It  is  true  that  both  corn  and  oats  are  some- 
times grown  for  fodder,  but  their  chief  value  to  man 
lies  in  their  seed. 

Corn,  wheat,  and  oats  are  found  growing  in  all  the 
temperate  regions  of  the  earth,  in  many  different 
kinds  of  soil  and  in  many  climates.  The  numerous 
soils  and  climates  in  which  the  crops  grow  have  pro- 
duced a  number  of  different  varieties;  thus  we  have 
dent  corn,  flint  corn,  popcorn,  etc.;  red  wheat,  white 
wheat,  bearded  wheat,  etc. ;  and  many  varieties  of  oats. 
But  while  these  varieties  differ  somewhat  in  appear- 
ance they  are  very  similar  in  habits  of  growth  and  food 
requirements. 

All  the  cereals  are  annuals,  and  have  clustered  or 
crown  roots,  as  shown  in  Fig.  5,  page  40.  These  roots 
branch  out  near  the  surface  and  spread  through  the 
surface  soil.  Some  of  the  roots  penetrate  to  consid- 
erable depths  in  the  subsoil;  the  roots  of  winter  wheat- 
plants  have  been  known  to  penetrate  the  soil  to  a 
depth  of  four  feet  or  more,  but  most  of  the  roots 
draw  their  supplies  of  food  and  water  from  the  upper 
soil. 


CEREAL  AND  FODDER  CROPS  159 

The  cereal  crops  grow  on  almost  any  kind  of  soil, 
lmt  thej  do  best  in  deep,  rich,  clay  loams  which  are  well 
Supplied  with  water,  hut  not  wet.  The  ideal  soils  for 
cereals  are  the  rich  prairie  soils  of  the  western  United 
States  and  eastern  Roiaia.  Whatever  the  kind  of  soil 
in  whieli  these  crops  are  to  be  grown,  it  should  be  well 
cultivated  in  order  to  give  the  roots  a  chance  to  spread. 
Hard,  rough  soils  give  the  roots  of  cereals  do  chance 
to  spread  in  search  of  food,  and  the  crops  suffer  in 
consequence.  Light,  sandy  soils  contain  neither  suffi- 
cient food  DO!  water  for  the  cereals.  The  cereal  crops 
are  best  planted  in  drills  or  rows.  When  planted  in 
this  way  a  better  yield  of  grain  per  acre  is  obtained 
than  if  the  seed  be  .scattered  over  the  surface. 

The  cereal  crops  require  an  abundant  supply  of 
nitrogen,  phosphoric  acid,  and  potash,  all  of  which 
thej  draw  from  the  soil    If  the  soil  be  poor  in  any 

one  of  these  plant    foods  the  deficiency  must   be  made 

good  by  the  use  of  fertilisers,  Fertilisers  containing 
available  nitrogen,  phosphoric  acid,  and  potash  com- 
pounds are  usually  found  of  benefit  to  the  cereal  crops. 
The   proper   amounts   and    proportions    of    thoe    three 

different  substances  depend  on  such  a  variety  of  cir- 
cumstances that  no  rules  for  their  use  can  be  stated 
here. 

While  corn  is  classed  I  il  crop,  it  differs  some- 

what in  it<  habits  of  growth  from  the  small  grains. 
Corn  is  planted  in  rows  some  distance  apart,  and  the 
crop  requires  thorough  but  shallow  cultivation  during 
its  period  of  growth.  The  small  grain  crops  require 
no  cultivation.    Corn  can  draw  much  of  its  food  from 


100  ELEMENTS    OP   AGRICULTURE 

the  decaying  organic  matter  in  the  soil,  and  in  conse- 
quence stable  manure  is  specially  valuable  as  a  manure 
for  this  crop. 

149.  Fodder  Crops. — Instead  of  gathering  the  seed 
for  food,  the  entire  crop  may  be  harvested  and  fed  to 
animals.  Crops  harvested  in  this  way  make  what  is 
known  as  fodder.  The  crop  may  be  gathered  before 
it  ripens,  and  may  be  fed  at  once,  when  it  is  known  as 
green  fodder;  or  it  may  be  dried  and  made  into 
dry  fodder.  The  most  important  fodder  crops  are 
corn  and  oats.  Thus  corn  and  oats  are  important  both 
as  cereal  and  fodder  crops. 

150.  Green  Fodder. — When  crops  are  cut  before  they 
ripen  and  are  at  once  fed  to  cattle  the  process  is  known 
as  soiling.  Any  crop  fit  for  cattle  food  may  be  used 
for  this  purpose — corn,  oats,  rye,  clover,  cowpeas,  etc. 
It  would  require  too  much  space  to  describe  the  many 
advantages  claimed  by  its  advocates  for  this  method 
of  feeding  cattle;  suffice  it  to  say,  the  method  is  grow- 
ing in  favor,  and  when  pasturage  is  scanty  may  be 
advantageously  practiced. 

151.  Ensilage  or  Silage. — Another  method  of  feeding 
green  fodder  is  to  preserve  it  as  ensilage  and  feed  it  to 
stock  during  the  winter  months.  Ensilage  is  made  by 
packing  awray  green  fodder  in  buildings  or  compart- 
ments called  silos,  which  are  large  pits  dug  in  the 
ground,  or  air-tight  rooms  built  above  ground.  The 
silo  most  generally  used  now  is  built  above  ground  in 
the  shape  of  an  immense  barrel.  A  round  silo  is  shown 
in  the  cut  of  the  model  barn.  (See  frontispiece.)  The 
best  constructed  silos  have  double  walls,  between  which 
are  layers  of  paper.    The  size  of  the  silo  is,  of  course, 


CI  id   \l      \\!>     I  (.I>I>KR    CBOP8  161 

regulated  by  the  amount  of  ensilage  to  be  stored  away. 
Before  tin*  fodder  il  put  into  tli*'  silo  it  should  !• 
up,  as  in  this  way  a  much  greater  quantity  can  be  stored, 
ami   the  air  more  thoroughly  excluded      Almost    any 
of  tin-  green  crops  may  be  used  to  make  ensilage  bntt 

com  fodder  cut  green  bai  been  found  to  he  the  best 
crop  for  tin*  purpose.  The  crop  is  best  cut  after  the 
ears  of  corn  hare  formed,  but  before  the  grains  have 
become  hard.  If  the  crop  is  cut  too  early  the  ensilage 
is  apt  to  become  too  acid  or  sour,  and  if  cut  when  the 
crop  ifl  mature  it  is  somewhat  hard  and  dry. 

Just  bow  th»-  ensilage  i-  preferred  in  the  silo  is  not 

thoroughly  understood,  hut  the  simplest  explanation 
is  as  follows:  When  the  ensilage  is  first  stored  in  the 
silo  it  begins  to  heat,  and  the  whole  mass  in  a  com- 
paratively short  time  becomes  thoroughly  warm.  Heat- 
ing always  take-  place  when  freshly  cut  green  fodder 
of  any  kind  is  beeped  together.    Borne  oi  the  countless 

ria   that    an-   promt    in   the  air  or   in   tin*   plants 

themsehr-  are  inevitably  packed  away  with  the  ensi- 
lage, and  when  the  mas«  begins  to  heat  they  begin  to 
work,  causing  fermentation,  the  tir>t  step  towards 
These  bacteria  are  supplied  with  oxygen  by  the 
air  that  fills  th  ;n  the  DUU  u   .     Hut  the 

heat  generated  expands  this  air  and  causes  much  of  it 
to  escape  through  the  top  of  the  mass.  The  ensilage 
settles  and  more  air  il  driven  out.  Between  the  loss 
of  escaping  air  and  that  Dsed  up  by  the  bacteria  them- 
selves, tin*  supply  is  soon  exhausted,  and  <»wing  to  a  lack 
of  oxygen  the  to  work  and  the  ensilage 

is  presen<  further  decay.    The  mass  of  ensilage 

11 


162 


ELEMENTS    OF    AGRICULTURE 


soon  settles,  becoming  so  tightly  packed  that  little  or 
no  air  can  enter.  The  top  of  the  silo,  except  for  a 
covering  from  the  rain,  may  be  kept  open  to  the  air, 
and  no  harm  will  result.  The  first  few  inches  of  ensi- 
lage which  are  exposed  to  the  air  will  rot,  but  the 
ensilage  will  be  found  perfectly  preserved  below.  A 
covering  of  straw  helps  to  preserve  the  top  layer  of 
ensilage.  The  slight  fermentation  that  has  taken  place 
in  the  ensilage,  it  is  claimed,  improves  it  as  a  food  for 
stock;  but  whether  this  is  true  or  not,  ensilage  is  much 
enjoyed  as  a  food  by  all  classes  of  stock. 

Ensilage  is  very  valuable  as  a  stock  food  because  it 
furnishes  a  supply  of  fresh  food  at  a  season  when  green 
food  is  unobtainable.  It  is  also  a  very  economical  way 
to  preserve  food,  for  by  this  process  great  quantities  of 
food  may  be  stored  in  a  very  small  space.  The  feeding 
of  ensilage  during  the  winter  months  is  beneficial  to 
the  health  of  animals.  While  ensilage  furnishes  a 
valuable  food  for  all  classes  of  stock,  it  is  especially 
valuable  for  milch  cows.  Feeding  ensilage  to  milch 
cows  causes  the  animals  to  give  a  greater  supply  of 
milk,  and  at  the  same  time  keeps  them  in  better  health. 

We  learn  from  Roman  writers  that  the  practice  of 
preserving  fodder  as  ensilage  is  a  very  old  one.  It  is 
probable  that  the  process  was  known  to  them  hun- 
dreds of  years  before  the  birth  of  Christ.  In  this 
country  ensilage  is  a  comparatively  new  thing,  the 
practice  having  been  begun  about  1875,  and  was  based 
upon  the  method  then  in  vogue  in  France.  It  rapidly 
grew  in  favor  until  now  a  silo  is  part  of  the  equipment 
of  every  first-class  farm  where  stock  is  kept.    The 


CEREAL  AND  FODDER  CROPS  163 

earlier  silos  were  merely  pits  dog  in  the  ground,  some 
of  them  lined  with  cement;  but  it  was  troublesome  to 
dig  the  ensilage  from  these  pits,  and  to  avoid  this  the 
silo  built  above  ground  came  into  use.  The  modern 
silo  is  usually  built  as  a  part  of  tin-  feeding  barn,  and 
on  a  level  with  the  feeding  floor.-  It  should  always  be 
situated  as  close  as  possible  to  the  feeding  stalls  on 
aooonnl  ol  the  labor  ol  handling  the  ensilage;  for  it  is 

hoth  heavy  and  bulky,  and  to  carry  it  by  hand  for  long 
distances  adds  materially  to  its  cost. 

Questions 

1.  Name  the  three  most  important  cereal  crops  of  this 
country.  2.  What  part  of  the  crop  is  of  most  value?  3.  In 
what  parts  of  the  earth  are  corn,  wheat,  and  oats  grown? 
4.  How  have  the  many  different  soils  and  climates  affected 
these  crops?  5.  What  sort  of  roots  have  the  cereals? 
6.  Name  two  regions  especially  noted  for  their  production 
of  grain.  7.  What  Is  meant  by  fodder?  8.  What  is  the 
difference  between  green  and  dry  fodder?  9.  What  is  feed- 
ing green  fodder  called?  10.  What  is  ensilage?  11.  What 
is  a  silo?  12.  How  should  the  crop  be  prepared  for  storage 
in  the  silo?  13.  Why  should  fodder  be  cut  up  before  storing 
for  ensilage?  14.  What  happens  to  the  fodder  when  it  is 
first  stored  in  the  silo?  15.  How  is  the  fermentation  of  the 
ensilage  stopped?  16.  Give  some  reasons  why  ensilage  is 
of  value  as  a  stock  food.  17.  About  how  old  is  the  practice 
of  making  ensilage?  18.  About  what  year  was  ensilage  first 
made  in  this  country? 


164 


ELEMENTS    OF    AGRICULTURE 


CHAPTER  XXX.— Fodder  Crops  and  Pastures 

152.  Dry  Fodder  or  Forage. — Dry  fodder  may  be- 
divided  into  three  classes:  Dry  coarse  fodder, 
straw,  and  hay. 

153.  Dry  Coarse  Fodder. — After  the  corn  crop  has 
been  cut  and  the  ears  gathered,  the  stalk,  leaves,  and 
shucks  form  what  is  generally  known  as  corn  fodder; 
a  better  name  for  it  is  corn  stover,  to  distinguish  it 
from  another  kind  of  corn  fodder.  When  corn  is 
planted  thick  like  wheat  or  oats,  the  plants  make  a 
fine  growth,  but  the  ears  do  not  develop  as  well  -as  when 
the  crop  is  planted  with  greater  space  between  the 
plants.  Corn  for  fodder  is  planted  thick  like  wheat, 
and  the  crop  is  cut  before  the  ears  are  fully  ripe;  it 
then  makes  the  true  corn  fodder.  Corn  fodder  is  made 
from  the  whole  plant,  ears  included;  it  is  the  hay  of  the 
corn  plant.  Corn  stover  is  made  from  the  plant  with- 
out the  ears;  it  is  the  straw  of  the  corn  plant.  Some- 
times the  ripened  leaves  only  are  gathered  for  fodder; 
they  make  what  is  known  as  pulled  fodder  or 
blades.  Oats,  millet,  and  sorghum  are  all  extensively 
used  for  making  fodder. 

154.  Straw.— Straw  is  that  part  of  the  cereal  crop 
which  remains  after  the  seed  has  been  gathered.  From 
the  corn  crop  it  is  known  as  stover,  but  from  wheat, 
oats,  rice,  rye,  barley,  etc.,  it  is  known  as  straw. 

Straw  is  not  of  great  value  as  a  stock  food%     The 


FODDER  CHOPS  AND   PASTURES  165 

• 

seed  wind)  have  been  gathered  take  away  most  of  the 
valuable  food  compounds,  leaving  the  straw  dry  and 
hard  Straw  can,  however,  be  used  to  advantage  as  a 
food,  as  will  be  explained  later,  and  is  also  valuable  as 
a  bedding  for  stock.  Old  or  rotting  straw  forms  a 
valuahlc  mulch  for  poor  soils. 

155.  Hay. — When  grasses,  clovers  and  similar  crops 
are  cut  green  and  dried  in  the  sun  they  form  what  we 
call  hay.  The  havs  formed  by  coarser  grasses  such 
as  corn  and  sorghum  are  called  fodder,  though  they  are 
nothing  more  than  hays.  Hay  differs  from  the  original 
green  fodder  in  having  lost  nearly  all  of  its  moisture. 

though  apparently  perfectly  dry,  contains  on  an 
ure  about  10  per  cent  of  moisture.    Of  course  there 
are  many  kinds  of  hay  resulting  from  the  many  kinds 
of  forage  plants,  but    we    may  divide    hays    into    two 
distil  ft,    namely,   the   hay  of  grasses  and   the 

hay  of  legumes. 

156.  Hay  of  Grasses. — There  are  many  kinds  of 
grasses  that  may  be  grown  for  hay — grasses  suitable  to 
different  soils  and  climates.  Among  the  best  known  hay 
grasses  are  timothy,  orchard  grass,  bluegrass,  meadow 
grasses,  and,  in  the  South,  Bermuda  grass.  Two  or 
more    kinds  of    grasses    may  be  grown  together,  and 

r  is  often  mixed  with  them.  The  hay  from  such 
a  mixture  is  (ailed  hay  of  mixed  grasses.  Most  of 
the  grasses  grown  for  hay  are  perennials;  each  year 
the  top  dies  to  the  -in face  soil,  but  the  next  spring  a 
fresh  growth  is  sent  up  by  the  roots.  The  grasses 
grown  for  hay  have  much  the  same  kind  of  roots  as  the 
cereal  crops  and  require  for  their  production  much  the 


166  ELEMENTS    OF    AGRICULTURE 

same  kinds  of  soils  and  fertilizers.  Fertilizers  contain- 
ing nitrogen  often  improve  crops  of  grass.  Grass  crops 
are  often  grown  immediately  succeeding  crops  of  wheat 
or  oats.  The  soil  is  or  should  be  already  well  prepared 
for  the  wheat  or  oats,  and  the  dense  growth  of  these 
crops  checks  the  growth  of  weeds,  leaving  the  soil  in 
good  condition  for  grass. 

Grass  that  is  mown  for  hay  should  not  be  exposed 
to  the  sun  for  days  after  being  cut.  The  object  in 
curing  hay  is  merely  to  remove  a  part  of  the  water 
contained  in  the  fresh  grass.  This  is  accomplished 
by  a  few  hours'  exposure- to  the  sun.  The  hay  should 
then  be  put  into  small  heaps  called  cocks;  after  stand- 
ing in  them  for  a  short  time  the  hay  should  be  stored 
away  in  barns  or  stacks.  It  is  a  great  mistake  to  allow 
cut  hay  to  lie  on  the  ground  for  days,  or  even  to  allow 
it  to  remain  for  any  length  of  time  in  cocks.  Through 
the  action  of  the  sun  and  weather  the  quality  of  the 
hay  is  much  injured.  The  grass  after  being  cut  dries 
out  very  fast,  and  the  entire  process  of  curing  and 
storing  hay  should  not  exceed  two  days. 

Grasses  should  generally  be  cut  for  hay  when  in  full 
bloom  or  just  passing  out  of  bloom,  as  at  this  time  the 
protein  and  carbohydrates  are  more  uniformly  dis- 
tributed throughout  the  plant. 

157.  Hay  of  Legumes. — Of  the  plants  belonging  to 
the  legumes,  there  are  a  number  that  may  be  used  for 
hay.  There  are  several  kinds  of  clover,  a  number  of 
kinds  of  field  peas  or  beans,  some  of  which  are  known 
under  the  name  of  cowpea.  Then  there  is  another  kind 
of  pea  called  vetch,  and  a  plant  of  the    same    order 


FODDEit  CROP8   AND   PASTURE8  167 

known  as  lucerne.  There  are  still  other  kinds  of 
legumes  used  for  hay,  but  the  tw<>  first  mentioned,  the 
vlnMv  and  oowpee,  aw  more  generally  used  in  tliis 
country  than  any  other. 

The  leguminous  cropi  used  for  hay  grow  in  almost 
all  soils  and  in  many  climates.  Some,  however,  do  best 
in  one  kind  of  soil  and  climate,  while  other  varieties 
prefer  very  different  conditions.  "  Clover  does  not  do 
well  in  hot  climates,  nor  does  it  produce  profitable 
erojM  from  poor  sandy  soils;  this  crop  prefers  a  good 
strong  soil  well  supplied  with  moisture,  lime,  and  pot- 
■th.  The  COW  pee,  on  the  other  hand,  does  not  mature 
in  cold  climates,  and  flourishes  best  under  the  hot 
southern  sun.  It  will  make  a  good  crop  on  soils  too 
poor  to  produce  clover.  Light  sandy  loams,  if  well 
supplied  with  moisture  and  mineral  plant  food,  will 
produce  large  crops  of  cowpeas. 

All  the  crops  belonging  to  the  pea  family  have,  as 
you  no  doubt  remember,  the  power  of  using  the  nitro- 
gen of  the  air  for  food.  They  can  therefore  grow 
well  in  soils  containing  little  nitrogen. 

These  crops  are  provided  with  very  deep-growing 
roots  which  spread  to  a  considerable  depth  through 
the  subsoil,  from  which  they  draw  much  plant  food. 
The  legumes  have  the  power  of  extracting  more  food 
from  the  soil  than  either  the  cereal  crops  or  grasses, 
and  their  deep-growing  roots  enable  them  better  to 
withstand  drought  These  crops  improve  the  condition 
of  the  >oil  by  adding  to  its  store  of  plant  food,  and 
also  make  a  very  valuable  hay  which  is  much  used  as 
cattle  food.     The  cowpea  has  been  called  the  "poor 


168  ELEMENTS    OF    AGRICULTURE 

man's  bank";  it  might  more  properly  have  been  called 
"the  poor  soil's  bank/'  for  from  it  the  poor  soil  draws 
fresh  supplies  of  plant  food. 

Among  the  legumes  are  included  annuals,  biennials, 
and  perennials!  The  variety  of  clover  usually  grown 
for  hay,  known  as  red  clover,  is  in  temperate  regions 
a  biennial.  White  clover,  the  small  clover  which  grows 
in  most  pastures,  is  a  perennial;  and  there  is  still 
another  kind,  known  as  crimson  clover,  which  is  an 
annual. 

Clover  should  be  cut  for  hay  when  in  full  bloom; 
the  peas  and  beans  should  be  cut  when  the  pods  are 
formed,  but  before  they  become  hard.  If  these  crops 
are  allowed  to  become  too  old  before  cutting,  the  leaves 
are  liable  to  drop  from  the  stem,  and  the  value  of  the 
hay  is  thereby  decreased. 

After  being  cut,  leguminous  crops  should  be  cured 
rapidly,  for  if  they  are  allowed  to  remain  in  the  sun 
for  many  hours  they  become  hard  and  brittle  so  that 
when  handled  the  leaves  drop  away  from  the  stem. 

158.  Pastures. — A  pasture  is  a  field  planted  in  any 
crop  on  which  animals  are  allowed  to  graze.  Pastures 
are  of  two  kinds,  permanent  and  temporary. 

159.  Permanent  Pastures. — Fields  on  which  peren- 
nial forage  crops  are  planted  and  allowed  to  grow  year 
after  year  are  called  permanent  pastures.  The  best 
kinds  of  pasture  grasses  form  a  very  thick,  dense  growth 
on  the  surface  of  the  soil,  while  below  the  surface  their 
roots  are  so  matted  together  that  sections  of  a  square 
foot  or  more  may  be  lifted  from  the  soil.  Such  a  growth 
forms  what  is  known  as  turf  or  sod.     A  good  turf 


FODDER  CROPS  AND   PASTURES  169 

forms  a  perfect  covering  for  the  soil  and  projects  it 
from  Mirl'aee  evaporation,  ;iinl  from  the  leaching  ;m<l 
Wishing  <»f  rains.     All  (  ill  not  make  good. turf; 

in  fact  then  are  comparatively  :■  iliat  form 

a  perfectly  even  turf  suitable  for  a  lawn.    On  pasture 

hinds,  however,  while  a  ,Lr<>:xl  turf  is  an  advantage  it  is 
not  a  necessity;  any  perennial  crop  that  will  cover  the 
surface  of  the  soil  and  furnish  food  for  stock  may  be 
used.     On  many  soils  it  is  impossible  except  at 

•<>  establish  a  good  turf,  but  there  ire  few  soils 
on  which  some  sort  of  a  pasture  cannot  he  established. 
Old  tiehls  thai  are  now  giren  over  to  weed-  and  gullies 

maw  with  pTOpei  Care,  be  converted  into  excellent  pas- 
Only  perennial  plants  should   be  used  to  form 

a  permanent  pasture;  annuals  ami  biennials  should  be 

avoided.  There  ITS  many  perennial  plants  Suitable  for 
permanent  pastures,  hut  it  would  require  too  much 
space  to  attempt  a  list  of  them  in  this  little  book.  The 
various  plant-  best  Mined  to  different  soils  ami  climates 

can   be  determined    .»nl\    1»\    actual    test.      The    Tinted 
G     .eminent    has  established  a   number  of  grass 

u   lor   the   purpose   of  determining   the   most 

valuable  forage  plants  for  different  Will  and  (  limates. 
There  are  a  number  of  inch  garden!  I  about  in 

this  country,  and    from   them   we   mav   learn    much   in 

i  to  the  furious  kinds  of  forage  plants. 

160.  Temporary  Pastures.— When  a  held  fa  planted 
in  some  crop  to  furnish  grazing  for  only  a  limited  time, 
m\  months  or  a  year  for  instance,  it  is  called  a  tem- 
porary pasture.    For  such  pastures  almost  any  forage 


170 


ELEMENTS    OF    AGRICULTURE 


crop  may  be  used;  annuals  or  biennials  serve  the  pur- 
pose as  well  as  perennials. 

The  growing  of  pasture  crops  is  the  least  exhausting 
method  of  cultivating  soils.  In  the  first  place,  all  the 
manure  from  the  grazing  animals  goes  directly  back 
to  the  soil.  In  the  second  place,  the  soil  is  well  pro- 
tected from  washing,  leaching,  and  surface  evaporation. 
The  only  plant  food  lost  to  the  soil  is  that  which  goes 
to  build  up  the  bodies  of  the  pastured  animals.  There 
are  fields  known  to  have  been  used  continuously  for 
pasture  for  one  hundred  years  or  more  that  are  to-day 
as  good  as  ever.  » 

Pastures  should  never  be  allowed  to  grow  up  in  weeds. 
The  weeds  should  be  kept  down  by  cutting  before  they 
ripen  seed;  or,  if  they  become  too  numerous,  the  field 
should  be  plowed  and  planted  for  a  time  in  some  culti- 
vated crop  such  as  corn  or  tobacco. 

Questions 

1.  Into  what  three  classes  can  dry  fodders  be  divided? 
2.  What  is  corn  stover?  3.  What  is  pulled  fodder?  4.  What 
is  corn  fodder?  5.  What  is  the  difference  between  corn 
stover  and  corn  fodder?  6.  What  is  straw?  7.  For  what 
is  straw  useful?  8.  What  is  hay?  9.  How  does  hay  differ 
from  the  original  green  forage?  10.  What  per  cent  of 
moisture  does  average  hay  contain?  11.  Name  the  two 
classes  into  which  hays  are  divided.  12.  Name  a  few  of  the 
best  grasses  for  hay.  13.  For  how  many  years  do  most  of 
the  grasses  used  for  hay  live?  14.  What  leguminous  crops 
are  grown  for  hay?  15.  How  do  the  roots  of  legumes  differ 
from  those  of  the  cereals  and  grasses?  16.  Why  are  they 
better  able  to  stand  dry  weather  than  the  grasses? 
17.  Why  is  the  cowpea  a  good  crop  for  poor  soils?  18.  What 


FODDER   CROPS   AND    I'AMi  171 

Is  meant  by  a  pasture?  19.  What  Is  permanent  pasture? 
20.  What  sort  of  crops  must  be  planted  to  form  a  perma- 
nent pasture?  21.  What  is  meant  by  a  turf?  22.  How  does 
turf  protect  the  soil?  23.  What  is  meant  by  a  grass  garden? 
24.  What  is  a  temporary  pasture?  25.  Why  does  not 
pasturing  exhaust  the  soil? 


172 


ELEMENTS    OF   AGRICULTURE 


CHAPTEK    XXXI.— Root  and  Tuber  Crops: 
Miscellaneous  Crops 

161.  Eoot  Crops. — The  roots  of  several  different  kinds 
of  crops  furnish  valuable  food  for  animals.  Turnips, 
beets,  and  carrots  are  all  grown  to  feed  animals;  and 
as  they  develop  late  in  the  fall,  they  furnish  fresh  food 
during  the  winter  months,  when  other  fresh  food  is 
scarce.  Radishes,  parsnips  and  salsify  are  much  grown 
in  gardens,  but  are  not  used  as  food  for  stock.  x\ll  of 
these  root  crops  are  biennials,  and  their  large  roots 
serve  mainly  as  a  storehouse  from  which  the  plant 
draws  its  seed-forming  materials  during  the  second 
season's  growth.  Root  crops  require  great  quantities 
of  water  for  their  growth ;  and  for  their  proper  develop- 
ment need  a  well  cultivated,  deep,  loamy  soil  in  which 
the  soft  roots  may  expand  and  reach  their  full  size. 
The  fresh  leaves  and  tops  of  root  crops  contain  large 
amounts  of  mineral  matter  which  the  plant  has  stored 
up  to  aid  in  forming  seed  the  second  season.  For  this 
reason  the  leaves  and  tops  should  always  be  returned 
to  the  soil;  if  they  are  not  returned  much  valuable 
plant  food  is  lost. 

The  soil  in  which  root  crops  are  growing  should  be 
kept  free  from  weeds,  and  must  be  well  supplied  with 
available  plant  food,  especially  with  phosphates. 

162.  Tuber  Crops. — The  two  important  tuber  crops 
are  the  sweet  and  the  Irish  potato.  The  sweet  potato  is 
really  a  root  crop,  but  instead  of  having  one  enlarged 


BOOT  am»  ti'iiki;  QX0P8,   RO. 


173 


taproot  it  has  clustered  roots  which  ire  enlarged.  The 
enlarged  portions  of  the  roots  are  called  tu! 
roott.  Fig.  G  (page  40)  shows  the  enlarged  roots  of 
the  sweet  potato.  The  enlarged  portions  are  provided 
with  small  rOOtletfl  which  draw  food  from  th« 
The  tubers  of  the  Irish  potato,  on  the  other  hand,  are 
not  true  roots;  they  are  the 
enlarged  parts  of  under- 
ground stems.  I  L 
shows  the  tuber  of  the  Irish 
potato,  and  you  will  notice 
that  the  tubers,  unlike  the 
tnberous  roots  of  the  sweet 
potato,  have  no  rootlets. 
Both  of  then  eropi  are  per- 
ennials; but  since  they  are 
grown  for  their  tab 
fresh  OOp  must  be  planted 
.  and  ai  cultivated 
I  tlitv  are  practically 
annuals.  Sweet  potatoes 
"are  sometimes  grown  for 
cattle  food,  but  Irish  potatoes  are  used  almost  exclu- 
mvcIv  for  human  food.  The  soil  best  suited  to  the 
sweet  potato  is  a  warm,  well-drained,  sandy  loam. 
This  crop  will  not  do  well  in  a  heavy  or  wet  soil.  The 
Irish  potato  requires  for  its  best  development  richer 
soil  than  the  sweet  potato.  For  both  crops  the  soil 
must  be  well  drained  and  cultivated,  and  well  supplied 
with  moisture,  though  not  wet.  The  sweet  potato  does 
best  in  a  temperate  or  warm  climate,  and  makes  but 


Fio.  2S.— Tubers  and  roots  of 
the  Irish  potato.  (Original  draw- 
ing from  photograph.) 


174 


ELEMENTS    OF    AGRICULTURE 


a  poor  growth  in  a  cold  one.  The  Irish  potato,  on  the 
other  hand,  does  best  in  a  cold  climate,  though  it  will 
grow  well  in  the  far  South. 

163.  Tobacco. — Of  the  many  crops  grown  on  the 
farm  besides  those  already  described,  we  have  space 
here  to  mention  only  a  few,  and  among  these  tobacco 
is  one  of  the  more  important. 

Tobacco,  which  is  an  annual,  can  be  grown  in  North 
America  all  the  way  from  the  equator  to  the  southern 
part  of  Canada,  and  in  many  kinds  of  soil.  This  great 
diversity  of  soil  and  climate  produces  a  number  of 
varieties  of  tobacco,  though  the  soil  seems  to  have  more 
influence  on  the  variety  of  tobacco  than  the  climate. 
Light  sandy  soils,  as  a  rule,  produce  a  small  bright- 
colored  leaf  that  is  much  esteemed  for  smoking  tobacco. 
The  heavier  clay  soils  produce  a  large  and  darker  leaf 
which  is  used  for  chewing  tobacco  and  snuff.  To  pro- 
duce a  successful  crop  of  tobacco  the  soil  must  be 
thoroughly  cultivated  and  kept  free  from  weeds,  and  the 
crop  must  be  well  supplied  with  available  plant  food. 
Because  of  the  large  amount  of  plant  food  it  contains, 
and  the  clean  method  of  cultivation  necessary,  tobacco 
is  an  exhausting  crop  to  the  soil.  It  should  not  be 
grown  year  after  year  on  the  same  soil,  but  should  be 
rotated  with  other  crops,  as  will  be  described  in  the 
next  chapter. 

164.  Cotton. — This  is  a  distinctly  Southern  crop  and 
cannot  be  grown  profitably  north  of  the  southern 
parts  of  Virginia  and  Kentucky.  Cotton  is  a  very 
exhausting  crop  on  the  soil  because  of  the  way 
it  is  cultivated,  and  because,  after  the  crop  is  gath- 


BOOT  AND  TUBER  CROPS,  ETC.         175 

ered,  the  soil  is  left  hare  to  the  action  of  the 
weather.  When  the  cottonseed  or  an  equivalent 
amount  <>f  cottonseed-meal  is  returned  to  the  soil  as 
manure,  the  crop  itself  does  not  rapidly  exhaust  the 
supply  <>f  plant  food  in  the  soil.  The  lint  or  ti! 
OOttOD  contains  such  a  small  amount  of  plant  f«»<Ml  that 
niiiiiy  crops  may  !>»•  TtOBCtOH  <1  from  the  Mil  he  fore  it 
becomes  exhausted.  Cotton  lint  is  almost  pure  cel- 
lulo>e,  ami  contains  very  little  ash.  Three  hundred 
pounds   of  lint    cotton,   considered   a    fair  crop   to   the 

acre,  contain  about  l  pound  of  nitrogen,  |  pound  of 

phosphoric  acid,  and  2J  pounds  of  potash.  If  the 
cotton  crop  removed  plant  food  at  this  rate  it  would 
take  a  long  time  to  impoverish  a  soil.  But  300  pounds 
of  lint  take  along  with  theni  650  pound-  »»f  seed  which 
contain  about  20  pounds  of  nitrogen,  G§  pounds  of 
phosphoric  acid,  and  ?3  pounds  of  potash.  The  lint 
and  seed  together  remove  from  the  soil  considerable 
amounts  of  plant  food  which  must  he  replaced  else  the 
soil  will  become  poor.  Cotton  lands  are  much  cv 
to  the  weather  during  the  winter  months,  and  it  is 
from  this  exposure  rather  than  from  any  demand 
ile-  crop  that  tliev  become  exhausted.  Land  should 
not  be  cropped  continuously  in  cotton  year  after  year. 
but  several  crops  should  be  rotated. 

165.  Garden  and  Fruit  Crops. — These  crops  are  of 
such  great  variety,  and  grow  in  BO  many  different  soils 
and  climates  that  it  would  require  too  much  space 
even  to  attempt  to  name  the  best  known  varieties  of 
either  fruits  or  vegetables. 

As  a  rule  garden  and  small  fruit  crops  require  warm, 


176  ELEMENTS    OP   AGRICULTURE 

rich  soils  well  supplied  with  organic  matter,  wood's 
mold  being  frequently  used  for  the  purpose.  Warm 
soils  enable  the  crops  to  get  an.  early  start  in  the 
spring  and  so  produce  an  early  harvest. 

Questions 

1.  Name  three  root  crops  grown  for  stock  food.  2.  Name 
three  other  root  crops  grown  for  vegetables.  3.  Are  these 
crops  annuals,  biennials  or  perennials?  4.  How  does  the 
enlarged  root  benefit  the  growth  of  the  plant?  5.  What 
kind  of  soil  do  root  crops  require?  6.  What  kind  of  matter 
do  the  leaves  and  tops  of  these  plants  contain?  7.  Name 
the  two  most  important  tuber  crops.  8.  Describe  the  roots 
of  the  sweet  potato.  9.  How  do  they  differ  from  the 
root  crops  already  mentioned?  10.  What  are  the  tubers  of 
the  Irish  potato?  11.  Are  these  crops  annuals,  biennials  or 
perennials?  12.  What  kind  of  soil  is  best  adapted  to  the 
sweet  potato?  13.  May  good  crops  of  either  sweet  or  Irish 
potatoes  be  grown  in  a  wet  soil?  14.  In  what  parts  of  this 
country  does  tobacco  grow?  15.  How  are  the  different 
varieties  of  tobacco  produced?  16.  Why  does  the  tobacco 
crop  exhaust  the  soil?  17.  In  what  part  of  the  country  does 
cotton  grow?  18.  Why  is  it  that  cotton  lands  soon  become 
exhausted?  19.  What  kinds  of  soil  are  best  suited  for 
garden  crops  and  small  fruit? 


BOTATION   OF   CROPS  177 


CHAPTER   \\ XI I. —Rotation  of  Crops 

166.  What  is  Meant  by  Eotation. — Rotation  means 
changing  annually  the  kind  of  crop  grown  upon  a 
given  soil,  the  change  being  usually  made  in  a  regular 
Order.  For  instance,  from  a  certain  field  a  crop  of 
tobacco  is  grown;  the  next  season  the  same  field  is 
planted  in  wheat,  and  the  next  in  clover;  the  year  after 
the  clover,  tobacco  may  be  again  grown,  then  wheat, 
and  after  the  wheat  clover  again.  Thus  a  rotation  of 
these  crops  is  practiced,  but  four  or  even  more  crops 
may  Km  need  in  a  rotation.  In  general  farming  rota- 
tion is  much  practiced,  but  in  special  farming  it  is 
unfortunately  seldom   u.-ed. 

167.  Benefits  of  Rotation. — Rotation  of  crops  when 
properly  practiced  may  be  of  benefit  to  the  soil  in 
many  ways: 

1.  The  way  in  which  soils  are  cultivated  varies  with 
different  crops.  Tobacco  and  cotton  for  instance  leave 
the  soil  quite  bare;  wheat  and  oats  have  a  thick  stubble 
and  large  crops  of  weeds  spring  up  as  soon  as  they  are 
gathered.  If  tobacco  or  cotton  be  grown  continuously 
on  one  field,  the  soil  suffers  from  washing  and  leach- 
ing. Tobacco  and  cotton  should  be  rotated  with  crops 
that  protect  the  soil,  such  as  wheat  and  oats. 

2.  Many  <  roj.s  have  shallow  roots  which  draw  most 
of  their  food  from  the  upper  soil.  If  neb  crops  are 
grown  continuously  on  a  field,  the  upper  soil  becomes 
exhausted  while  the  lower  soil  is  untouched.     Crops 

12 


178 


ELEMENTS    OF    AGRICULTURE 


with  shallow  growing  roots  should  be  rotated  with 
crops  that  have  deep  roots.  Deep-growing  roots  draw 
much  food  from  the  subsoil. 

3.  Some  crops  require  specially  large,  amounts  of 
some  particular  plant  food.  Thus  tobacco  requires 
about  ten  times  as  much  potash  as  phosphoric  acid, 
and  if  such  a  crop  be  grown  continuously  upon  a  soil 
the  potash  becomes  exhausted  before  the  phosphoric 
acid.  Tobacco  should  be  rotated  with  some  crop  that 
requires  large  amounts  of  phosphates — wheat,  for  in- 
stance. 

4.  From  the  growth  of  some  crops  the  soil  becomes 
infested  with  weeds.  Thus  daises  or  wild  carrots  may 
become  very  numerous  in  a  pasture  or  hayfield.  When 
weeds  become  too  numerous  the  field  should  be  planted 
in  some  cleanly  cultivated  crop,  such  as  corn,  tobacco, 
or  cotton. 

5.  Many  crops  have  special  insect  enemies  that  feed 
upon  them.  Thus  tobacco  has  the  tobacco  worm, 
wheat  the  Hessian  fly,  potatoes  the  potato  beetle,  and 
almost  every  crop  grown  has  its  special  enemies  among 
the  thousands  of  insects  found  on  the  farm.  If  the 
same  crop  be  grown  upon  a  field  year  after  year,  these 
insect  enemies  increase,  for*they  are  supplied  with  just 
the  food  they  require.  If,  however,  the  kind  of  crop 
be  changed,  the  insects  suffer.  A  tobacco  worm  hatched 
in  a  wheat  field  finds  nothing  to  feed  on,  and  a  potato 
beetle  starves  in  a  tobacco  patch. 

0.  Most  crops  are  subject  to  attacks  of  some  special 
disease  which  may  not  affect  other  crops.  Wheat 
suffers  from  a  disease  called  rust,  but  tobacco  is  not 


ROTATION    OF   CROP8  170 

effected  by  it.    Corn  lunVri  from  input,  but  tobacco 
docs  not.    These  plant  diseases  spread  much  tt  din 
spread  among  human  beings  and  animals.     Thus  per- 
Bona  occupying  i  room  previously  occupied  by  ;i  man 
Buffering  with  a  contagious  disease   like   smallpox  or 

BCarlel  fever  arc  liable  to  contract  tlic  disease,  The 
room  is  said  to  D6  infected  by  the  -disease,  and  in  ■ 
similar  way  soils  become  infected  bv  plant  diseases. 
Wheat,  for  instance,  when  grown  on  a  soil  which  the 
year  before  produced  a  crop  of  wheat  affected  by  rust, 
is  liable  to  contraci  the  disease.  But  if  some  other 
crop  is  planted  which  is  not  liable  to  this  disease  there 
is  no  danger.  A  proper  rotation  of  crops,  for  the  rea- 
itated,  checks  the  spread  of  plant  disea- 
168.  Examples  of  Rotation. — The  crops  used  in  rota- 
tion must,  of  course,  be  determined  bv  the  kind  of 
crops  it  Ei  desired  to  grow.  The  following  examples 
have  been  found  satisfactory: 

ition   1.- -Firs!   year  tobae.o,  second  year  wheat, 
third  year  wheat,  fourth  and  fifth  years  cl<>\ 

Rotation  2, — First  year  corn,  second  year  oats,  third 
\ear  wheat,   fourth  and   fifth  years  clo\er. 

Rotation  3. — First  year  tobacco,  m  ir  wheat, 

third  and   fourth  years  clover. 

ti«>n    1. —  Fir-  n,  second   year   wheat, 

third  and   fourth  years  eloi 

i   year  cotton,  second  year  wheat, 
third  and  fourth  years  clo 

In  rotations  cowpeas  or  any  other  >uitablc  legumi- 
nous crop  ma;  1  in  place  of  clover. 


180 


ELEMENTS    OF    AGRICULTURE 


This  simple  diagram  serves  to  illustrate  a  common 
rotation  which  is  usually  called  the  four-shift  system: 


First 
Field. 

Second 
Field. 

Third 
Field. 

Fourth 
Field. 

First  year.. . 

Second  year 

Third  year 

Fourth   year.  . .  . 

Corn. 
Wheat. 
Clover. 
Clover. 

Wheat. 
Clover. 
Clover. 
Corn. 

Clover. 
Clover. 
Corn. 
Wheat. 

Clover. 
Corn. 
Wheat. 
Clover. 

Questions 

1.  What  is  meant  by  a  rotation  of  crops?  2.  Give  an  ex- 
ample of  rotation.  3.  In  what  kind  of  farming  is  rotation 
of  crops  much  practiced?  4.  Clean  cultivation  exposes  the 
soil  to  what  danger?  5.  How  does  rotation  lessen  the 
danger  arising  from  clean  cultivation?  6.  Why  is  it  best 
to  grew  a  crop  with  deep-growing  roots  after  a  crop  with 
shallow  roots?  7.  When  one  crop  is  grown  continuously, 
is  the  drain  upon  the  soil's  supply  of  plant  food  uniform? 
8.  How  is  this  irregularity  corrected  by  rotation?  9.  How 
does  rotation  check  the  spread  of  weeds?  10.  How  does 
rotation  check  the  spread  of  injurious  insects?  How  does 
rotation  check  plant  diseases?  11.  Is  rotation  of  crops  prac- 
ticed in  your  neighborhood?     12.  Give  a  few  examples  of 

rotation. 

PROBLEM 


Make  a  diagram  showing  a  five-shift  rotation  consisting 
of  corn,  oats,  wheat/  and  two  years  clover. 


UNIVERSITY 
of 
CAUFOP**i£r6bMPOSITION  OF  ANIMALS  181 


PART  VI.— Animal  Production 


CHAPTER  XXXI 1 1. —Composition  of  Animals 

169.  Stock  Farming. — Farm  crops  are  either  sold 
direct  from  the  farm,  or  else  turned  into  animals  OT 
animal  products,  which  are  sold.  The  latter  practice 
is  called  STOCK  FARMING,  only  such  crop*  being  gTOWD 
a<  are  needed  to  feed  the  animals.     This  is  the  highest 

order  of  farming,  as  it  requires  no1  only  ■  knowledge 

of  how  to  grow  crops,  hut  of  how  to  breed  and  feed 
animals.  The  stock  farmer  is  both  a  grower  of  crops 
and  a  manufacturer  of  fl.-h.  There  are  many  kinds 
of  stock   farms;   for  instance  there    are    cattle    farms, 

•beep  farms,  goat  farms,  horse  farms,  poultry  farms, 
and  dairy  farms,  all  run  for  the  production  of  animals. 
Almost  even  fanner  i-  more  or  lead  a  llock  rai>cr,  for 
some  animals  must  he  kept  on  every  farm  to  help  with 
the  farm  work  It  H  important  that  all  fanners  should 
know  how  to  feed  and  eare  for  animals,  and  for 
farmers  >uch  knowledge  il  absolutely  BOCOBBary.  Iii 
order  to  feed  animals  to  the  Deal  advantage  it  i*  well 
to  know  Something  of  the  animal's  body  and  how  it 
is  built  up. 

170.  Composition  of  Animal  Bodies. — Bonei  and  flesh 
make  up  a  large  part  of  the  bodies  of  animals;    the 
bones  servo  as  a  sort  of  framework  which    the    lash 
binds  together.    Through  the  flesh  run  the  m  r\- 
blood  vessels — veins  and  arteries;  and,  protected  by  the 


182  ELEMENTS    OP   AGRICULTURE 

flesh  and  bones,  are  found  the  vital  organs — the  brain, 
the  heart,  lungs,  digestive  organs,  etc.  Covering  the 
body  is  the  skin,  which  is  in  turn  often  covered  by  hair 
or  feathers.  The  limbs  are  provided  with  hoofs  or 
claws,  and  from  the  heads  of  many  animals  grow  horns. 
These  various  parts  of  the  animal  bodies,  which  are  so 
different  in  appearance,  are  quite  different  in  composi- 
tion, though  they  all  contain  certain  substances  in 
common. 

171.  Moisture. — All  parts  of  the  animal  body  con- 
tain moisture;  even  the  apparently  dry  bones  contain 
some  moisture,  and  some  parts  of  the  body  contain 
large  quantities  of  water.  Young  animals,  like  young 
plants,  contain  more  moisture  than  they  do  when  they 
grow  older.  When  the  flesh  of  animals  is  dried  out  it 
forms  cured  meat.  Most  of  us  are  familiar  with  the 
dried  beef  which  is  sold  on  the  market  as  "chip-beef." 
This  process  of  curing  meat  is  similar  to  curing  grass 
for  hay;  in  both  cases  most  of  the  moisture  is  driven 
off.  The  flesh  of  most  animals  usually  contains  from 
40  to  60  per  cent  of  water,  seldom  more  than  60  per 
cent.  The  bones  of  course  contain  less  moisture  than 
the  flesh,  and  the  blood  contains  much  more.  The 
bodies  of  most  domestic  animals  contain  about  50  per 
cent  of  water,  not  counting  the  contents  of  the  stomach. 
That  part  of  the  animal  body  which  remains  after  the 
water  is  driven  off  is  called  dry  matter. 

172.  Dry  Matter. — When  the  dry  matter  of  animal 
bodies  is  burned  the  greater  part  disappears  into  the 
air  as  gas  and  smoke,  leaving  behind  a  small  quantity 
of  ash.     The  part  disappearing  into  the  air  is  called 


COMPOSITION   OF  ANIMAL8  183 

organic  matter  or  volatile  matter,  and  the  pari  remain- 
ing as  ash  is  called  inorganic  matter,  mineral  matter,  or 

■ah. 

173.  Organic  Matter. — The  organic.  Of  \olatile 
matter,  of  animal  bodies  may  be  divided  into  two 
classes  of  compounds,  one  class  containing  nitrogen, 
and  the  other  containing  no  nitrogen.  Jnff  as  in  the 
case  of  plant.-,  the  nitrogen-containing  compound*  are 
called  protein,  and  the  compounds  containing  no  nitro- 
gen are  called  non-nit rogenoUfl  substances.  These  eom- 
ponmls  arc,  however,  quite  different  in  appearance  from 
those  found  in  plants,  though  they  are  made  up  of  the 
same  elements.    The  relative  proportions  of  these  iw<> 

e  of   substances    ere    quite    different   in  animal 

bodies  from  what  they  arc  in  plants.  In  nearly  all 
plants  there  ire  more  of  non-nitrogenous  compounds 
than  of  DitrogenOUS;  hut  in  animals  the  reverse  i-  true. 

The  animal  body  contains  as  a  rule  more  nitrogenous 

substances  than  non-nitrogenoue, 

174.  Nitrogenous     Substances:     Protein. — The    drv 

matter  of  the  mu-cles,  nerves,  and   tendon-,  of  animal 

bodies  i>  made  op  almost  entirely  of  nitrogen  com- 
pounds.     The   hoofs,    horns,   claws,   skin,   blood,    hair, 

and  bones  contain  considerable  amounts  of  niti 

The  greater  part  of  the  bodies  oi  animals  is  made  up 
of  Compounds  <»f  DitrOgeO,  though  of  course  the  ditTer- 
ent  parts  of  the  body  contain  different  smounts.     The 

-  ami  skin,  for  instance,  contain  less  nitrogen  than 
the  hesn.    These  nitrogen  compounds  of  animal  bodies 

are  made  up  of  exactly  the  same  elements  that  make 
up  those  of  plants;  namely,  carbon,  oxygen,  bydr 


184 


ELEMENTS    OF    AGRICULTURE 


nitrogen,  sulphur,  and  a  litttle  phosphorus.  But 
though  they  are  made  up  of  the  same  elements,  they 
are  different  compounds,  and  differ  in  appearance  and 
in  the  proportions  in  which  the  elements  are  combined. 
The  nitrogen  compounds  are  by  far  the  mosjt  important 
compounds  of  the  animal  body. 

175.  Non-Nitrogenous  Substances. — The  non-nitrog- 
enous matter  of  plants  is  made  up  principally  of  starch, 
sugar,  gum,  and  woody  matter,  usually  with  small 
quantities  of  oil  or  fat.  In  animal  bodies,  on  the  other 
hand,  nearly  all  of  this  matter  is  fat  or  oil.  No  starch 
or  woody  matter  is  found  in  animal  bodies,  and  only  a 
little  sugar. 

The  amount  of  fat  in  animal  bodies  varies  greatly. 
Different  animals  contain  very  different  amounts  of  fat, 
and  the  same  body  varies  from  day  to  day  in  the 
amount  of  fat  it  contains.  The  non-nitrogenous  mat- 
ter of  animal  bodies  is  made  up  of  the  same  elements 
as  the  non-nitrogenous  matter  of  plants;  namely,  car- 
bon, hydrogen,  and  oxygen.  These  elements  are,  how- 
ever, combined  in  a  different  way,  and  the  fats  of 
animal  bodies  are  different  in  appearance  from  the 
fats  of  plants.  Thus  lard  is  quite  a  different  thing 
from  cottonseed  oil,  though  they  both  contain  the  same 
elements. 

176.  Mineral  Matter,  or  Ash. — Most  of  the  mineral 
matter  of  animal  bodies  is  contained  in  the  bones,  and 
only  small  quantities  are  found  in  the  flesh  and  blood. 
Older  animals  as  a  rule  contain  more  ash  than  younger 
animals.  This  is  because  their  bones  are  larger  and 
better  developed.    As  a  large  part  of  the  bones  of  all 


CUM  POSITION   OK    ANIMALS  185 

animals  is  made  Dp  of  phosphate*!  the  tell  of  animal 
bodiei  coniiatfl  lergety  o!  phosphate.    Ash  makei  up 

about  2  to  5  per  eent  «>f  animal  bodies.  The  ash  of 
animal  bodiei  contains  small  quantities  of  most  of  the 
elements  found  in  the  ashes  of  plants.  The  phosphates 
make  up  about  80  per  eent  "1"  the  ash. 

Questions 

1.  What  is  meant  by  stock  farming?  2.  Name  some  of  the 
various  kinds  of  stock  farms.  3.  Name  some  of  the  princi- 
pal substances  that  make  up  animal  bodies.  4.  In  what  does 
the  process  of  curing  meat  resemble  that  of  curing  hay? 
5.  As  a  rule,  do  animal  bodies  contain  as  much  moisture 
as  plants?  6.  What  two  classes  of  compounds  make  up  the 
dry  matter  of  animal  bodies?  7.  Divide  the  organic  matter 
into  two  classes  of  substances.  8.  What  part  of  the  flesh  is 
made  up  largely  of  protein?  9.  In  what  other  parts  of  the 
body  is  protein  found?  10.  As  a  rule,  which  contain  the 
more  protein,  animal  bodies  or  plants?  11.  What  elements 
make  up  protein?  12.  What  substance  makes  rp  most  of  the 
non-nitrogenous  matter  of  animal  bodies?  13.  Is  starch  or 
woody  matter  found  in  animal  bodies?  14.  In  what  part  of 
animal  bodies  is  most  of  the  mineral  matter  found? 


186  ELEMENTS    OF   AGRICULTURE 


CHAPTER  XXXIV.— Food,   Work,  and   Growth 
of  Animals 

177.  Animals  and  Plants  are  Alike  in  Composition. — 

In  the  last  chapter  we  learned  that  in  composition 
animal  bodies  closely  resemble  plants.  This  is  not  sur- 
prising when  we  consider  the  fact  that  the  food  of 
animals  consists  principally  of  plants.  It  is  true  that 
some  animals  are  carnivorous,  that  is,  they  live  on  the 
flesh  of  other  animals,  but  the  animals  so  used  for  food 
derive  their  food  from  plants. 

178.  Plants  Manufacture  Food  for  Animals. — While 
plants  and  animals  are  much  alike  in  composition  they 
differ  very  much  in  their  manner  of  taking  in  food  and 
growing.  Plants  as  a  rule  take  up  the  necessary  raw 
materials  from  the  earth  and  air,  and  change  them 
into  the  compounds  which  make  up  their  supply  of 
protein,  carbohydrates,  fats,  etc.  Animals  as  a  rule 
have  not  this  power  of  taking  the  raw  materials  into 
their  bodies  and  changing  them  into  other  compounds. 
A  horse  or  cow  will  starve  on  the  food  that  supplies 
plantsj  even  though  this  food  contains  all  the  elements 
found  in  the  animal's  body.  The  raw  materials  of  the 
earth  and  air  must  first  be  made  into  plants  before  they 
are  fit  food  for  animals.  Plants  are  the  makers  of 
animal  food. 

179.  All  Living  Animals  are  Constantly  Growing. — 
The  growth  of  young  animals  is  generally  rapid;  they 
increase  in  size  till  they  reach  the  point  where  they 


»OOD,    WORK,    AND  GROWTH   OF   A.N1MAL8        187 

apparently  cease  to  grow,  but  in  reality  they  go  on 
growing,  though  their  size  remains  about  constant. 
They  are  continually  repairing  and  rebuilding  the  worn 
places  in  their  bodies;  twice  each  year  a  new  crop  of 
hair  is  grown,  the  various  muscles  are  constantly  re- 
newed, and  in  this  way  the  body  is  continually  grow- 
ing. These  repairs  and  changes  cease  only  when  the 
animal  dies.  Life  means  change  and  constant  repair- 
ing; an  addition  of  now  growth  and  a  replacing  of  old 
parts  by  Dew.  In  plants  these  changes  usually  mean 
the  addition  of  new  growth,  most  plants  continuing  to 
increase  in  size  so  long  as  they  live.  Most  animals,  on 
the  other  hand,  reach  a  fixed  point  where  they  cease 
to  grow  in  size,  and  such  changes  in  the  bodies  as  take 
place  consist  in  renewing  worn  par 

180.  Food  Necessary  for  Growth. — To  effect  the 
change!  that  are  constantly  taking  place  in  the  animal 
body  a  constant  supply  of  the  proper  kinds  of  food  is 

ii \.  Not  only  is  food  necessary  for  the  repairs 
that  are  constantly  going  on,  but  it  is  necessary  to  keep 
uj>  the  temperature  of  the  body.  If  the  temperature 
of  an  animal's  body  if  mueh  reduced,  a  chill  ii  the  result 
and  sickness  usually  follows.  Food  and  a  proper  supply 
of  fresh  air  are  necessary  to  prevent  the  cooling  off  of 
the  animal  body. 

181.  Food  Necessary  for  Work. — Food  and  air  are 
also  necessary  t<>  enable  the  animal  to  use  its  muscles 
in  moving  ftbont  The  animal  body  has  often  been 
compared  to  a  steam  engine.  Feed  an  engine  fuel, 
water,  and  air.  and  it  <W>  work;  take  away  its  supply 
of  any  one  of  these  three  things,  it  ceases  to  move,  and 


188  ELEMENTS   OF   AGRICULTURE 

is  said  to  be  dead.  The  animal  body  requires  food, 
water,  and  air,  and  when  supplied  with  them  it  can 
move  about  and  do  work.  Take  away  any  one  of  them, 
and  the  body  soon  becomes  unable  to  move,  and  dies. 
182.  How  to  Feed  Animals. — The  art  of  feeding 
animals  is  knowing  how  to  supply  them  with  the  proper 
amounts  and  kinds  of  food.  Different  kinds  of  animals 
of  course  require  different  amounts  of  food.  A  cow 
or  a  steer  can  eat  at  one  time  much  more  food  than  a 
horse,  and  a  horse  can  eat  more  than  a  sheep.  Then, 
too,  the  same  kind  of  animal  under  different  conditions 
requires  different  amounts  of  food.  A  working  horse 
requires  more  and  better  food  than  a  horse  that  is 
doing  nothing.  A  cow  giving  milk  requires  more  food 
than  a  dry  cow.  To  grow  and  feed  animals  successfully, 
all  these  things  must  be  considered.  In  feeding  stock 
one  thing  that  should  especially  be  considered  is  the 
fact  that  scrubby  animals  eat  just  as  much  as  fine, 
well-bred  stock.  A  cow  giving  2  or  3  quarts  of  milk 
a  day  will  eat  just  about  as  much  as  a  cow  giving  two 
gallons.  A  cow  giving  an  average  of  3  quarts  of  milk 
a  day  will  produce  in  six  months  about  137  gallons, 
which  at  20  cents  a  gallon  would  be  worth  just  $27.40. 
A  cow  giving  an  average  of  2  gallons  of  milk  a  day  will 
produce  in  the  same  length  of  time  365  gallons,  which 
at  20  cents  would  be  worth  $73.00.  The  food  of  each 
is  about  equal  in  cost,  yet  the  milk  produced  by  the 
better  cow  is  worth  $45.60  more  than  the  milk  produced 
by  the  scrub.  The  scrub  costs  as  much  to  feed  as  the 
good  cow  and  does  less  than  half  the  work;  she  is, 
therefore*  more  than  twice  as  expensive  to  keep.     A 


FOOD,    WORK,    AND    GROWTH    OF   ANIMAL8         189 

lit tli  half-grown  •runt"  of  a  horse  may  eat  nearly  as 
much  as  a  line  powerful  draft  horse,  and  yd  not  be 
al.lo  to  do  half  the  work.  Jt  i>,  therefore,  just  about 
nsive  to  keep.  The  poorer  the  class  of 
stock  the  more  expensive  it  is  to  keep. 

Questions 

1.  The  food  of  most  animals  consists  of  what?  2.  How 
do  the  foods  of  animals  differ  from  the  foods  of  plants? 
3.  How  are  the  raw  materials  of  the  earth  and  air  con- 
verted into  animal  foods?  4.  Do  living  animals  ever  cease 
to  grow?  5.  What  changes  are  constantly  going  on  in  the 
bodies  of  animals?  6.  To  effect  the  changes  in  animal 
bodies  what  is  necessary?  7.  What  is  necessary  to  keep 
up  the  temperature  of  animal  bodies?  8.  What  three  things 
are  necessary  to  enable  an  animal  to  work?  9.  Why  is  it 
more  expensive  to  keep  scrub  stock  than  it  is  to  keep  more 
valuable  animals? 

PROBLEM 

Let  us  suppose  that  we  have  to  feed  two  milch  cows,  A 
and  B.  They  both  eat  about  the  same  amount  of  food  and 
cost  the  same  to  keep.  A,  however,  gives  an  average  of 
3  gallons  of  milk  a  day,  while  B  gives  only  an  average  of 
7  quarts..  Milk  is  worth  20  cents  a  gallon.  What  is  the  ap- 
proximate value  of  the  milk  produced  in  a  month  of  30  days 
by  each  cow? 


190  ELEMENTS    OF   AGRICULTURE 


CHAPTEE  XXXV.— Care  of  Animals 

183.  Care  as  Important  as  Feeding. — In  the  last 
chapter  you  were  told  that  the  art  of  feeding  is  know- 
ing how  to  supply  the  animal  with  the  pToper  amounts 
and  kinds  of  food.  There  are  several  ways  of  supply- 
ing the  animal  with  food;  it  may  be  turned  out  to  pas- 
ture, or  it  may  be  kept  in  the  stable,  and  the  food 
given  it,  but  whatever  the  method  adopted  the  animal 
should  be  well  treated.  If  the  animal  is  abused  or 
neglected  it  will  suffer,  no  matter  how  well  the  actual 
feeding  is  done.  Good  feeding  does  not  consist  simply 
in  good  food;  it  means  good  attention  and  kindness 
as  well.  If  the  animal  is  to  be  kept  in  a  stable,  the 
first  care  should  be  to  provide  a  comfortable  stable. 

184.  Stables. — Children  and  plants  cannot'  develop 
without  fresh  air  and  sunshine;  the  same  is  true  of 
domestic  animals.  To  keep  animals  shut  up  in  foul, 
dark,  ill-ventilated  stables  and  expect  them  to  grow 
and  do  well  is  as  foolish  as  attempting  to  grow  wheat 
in  a  cellar.  Yet  how  many  animals  are  provided  with 
comfortable  stables?  Once  a  year  is  usually  consid- 
ered often  enough  to  clean  a  stable.  The  air  is  nearly 
always  saturated  with  the  odor  of  decaying  organic 
matter.  The  light  of  day  seldom  penetrates  its  foul 
interior,  and  here  the  poor  animals  must  spend  a  large 
part  of  their  lives.  Is  it  any  wonder  that  so  many 
cattle  suffer  from  consumption,  and  through  their  flesh 
and  milk  transmit  this  fatal  disease  to  man?    All  ani- 


OABB   OF    ANIMAL8 


191 


mals  are  cleanly  in  their  habits,  and  there  are  few 
\\c  animals  that  would  of  their  own  accord  live 
in  the  foul  stablei  often  presided  for  their  use  by 
thoughtless  owners.  There  is  s  popular  belief  that  a 
man's  character  may  be  judged  by  the  way  he  treats 
his  beasts.  Lei  OS  hope  that  this  is  not  altogether  true, 
for  it  is  terrible  to  think  that  the  stock  owners  of  this 
country  are  possessed  of  <  ha  meters  as  foul  as  the 
Stables  they  provide  for  their  animaN. 

All   st  a  hies  should   if  possible  be  well   lighted  and 
ventilated,  ;ind  should  always  he  kepi  'lean,     Kach  day 

fresh  bedding  should  be  provided  for  the  animal,  no 
matter  whether  the  old  bedding  is  thrown  out  or  re- 
tained. The  floor  of  the  stable  should  be  kept  as  dry 
as  possible. 

185.  Kindness  to  Animals. — K indue—    i-   oecc 
to    the    successful    feeding   of    doiuestie    animals.       Do- 
C  animals  thai  are  well  treated  are  nearly  always 
gentle,  and  easily  handled  and   fed.     They  enjoy  their 

food,  and  by  their  improved  condition  ami  good  be- 
havior more  than  repaj  tin*  kindness  shown  them.  <»■! 
the  other  hand,  ill  treatment  almost  invariably  eauses 
the  animals  to  lose  Bosh.    Prom  blows  and  sbuse  they 

me  irritable,  often  \irious,  ami  ditheult  to  manage. 

The  Dervoas  worry  caused  by  ill  treatment  brings  on 

Indigestion,   and    loss   of   flesh    result  I         man   who 

illtreats  his  animaN  pays  for  it  oui  <»f  his  own  p 

only  docs  he  lots  tin-  respect  of  all  right-minded 
people,  but  be  actually  loses  money  because  -»f  the  de- 
crease in  value  of  his  stock.  It  is  an  invariable  rule 
that  animals  under  kind  treatment  can  do  more  work 


192 


ELEMENTS    OF   AGRICULTURE 


than  when  abused.  Systematic  beating  or  abuse  de- 
creases the  value  of  an  animal  many  dollars.  The 
utterly  senseless  and  cruel  practice  of  using  checkreins 
to  force  horses  to  hold  up  their  heads  in  an  unnatu- 
ral position  cannot  be  too  strongly  condemned.  The 
checkrein  should  be  banished  from  all  well-regulated 
farms. 

186.  Treatment  of  Cows. — The  cow  is  very  sensitive 
to  ill  treatment.  One  of  the  dairy  experts  of  this 
country,  after  a  careful  study  of  milch  cows,  says: 
"The  elaboration  [formation]  of  milk  does  not  pro- 
ceed at  a  uniform  rate  from  milking  to  milking,  but  is 
most  active  at  the  time  of  milking,  and  is  dependent 
not  only  upon  the  stimulus  which  the  milk  glands  derive 
from  the  manipulation  of  the  teats  and  udder,  but  upon 
the  nervous  condition  of  the  animal  at  the  time  of 
milking. 

"In  consequence  of  this,  slight  changes  in  the  con- 
dition under  which  the  milking  is  done  may  have  a 
decided  influence  upon  both  the  yield  and  quality  of 
the  milk/'  He  says  further :  "  It  is  my  opinion  that 
kind  treatment  and  pleasant  surroundings  will  have  a 
greater  influence  upon  the  quality  of  milk  than  the 
kind  of  food,  provided  the  rations  given  contain  suffi- 
cient nutrients  for  the  maintenance  of  the  animal."* 

187.  Regularity  and  System. — All  animals  should 
be  fed  and  watered  regularly,  and  it  is  very  important 
that  cows  should  be  milked  at  regular  intervals.  Most 
animals  form  habits  quickly,  and  soon  learn  when  to 


♦Professor  Babcock  in  the  Wisconsin  Station  Report  for  1889. 


CARE    OF   ANIMALS  193 

expect  their  food  and  exercise.  Changing  suddenly  the 
time  and  manner  of  feeding  disturb-  the  animals,  mak- 
ing them  restless  ami  uneasy,  Changing  tin*  time  or 
manner  of  milking  often  has  a  bad  effect  on  the  quan- 
tity or  quality  of  milk. 

188.  Exercise  and  Air. — All  animals  confined  in 
stables  should  be  given  a  certain  amount  of  daily  exer- 
cise and  fresh  air.  Fattening  cattle  require  but  little 
exercise,  but  they  need  fresh  air  ami  sunshine.     Milch 

do  best  when  they  haw  a  Few  hours  in  which  to 
walk  about  and  exercise  their  muscles.  Animals  con- 
fined in  close  stalls  have  little  opportunity  to  keep  their 
>kin-  clean  by  licking  themselves.  The  habit  animals 
have  of  licking  their  skins  is  as  important  to  them  as 
bathing  is -to  human  beings,  When  they  cannot  lick 
khemsetfei  thej  nrffer  as  nm.li  or  more  than  people' 
who  have  no  opportunity  of  washing  their  skins.  Brush- 
ing the  animals  each  day  may  partially  take  the  place 
of  their  licking1. 

189.  Exposure  to  the  Weather. — Many  persona  ap- 
pear to  ha\e  the  idea  that  domestic  animal-  ran  endure 
without  injury  any  amount  of  exposure  to  the  weather. 
Horses  that   have  Income  \.tv  warm   from  much 

cise  are  left  to  cool  otr  in  the  coldest  weather  with  no 
protection  khan  their  own  moist  skin-.  Cattle 
of  all  kind-  and  aire-  are  left  out  to  face  the  eoldesl 
blizzards,  or  are  kept  in  draughty  stable-.  Many  ani- 
mal- can  endure  exposure  of  this  kind,  just  aa 

•is   of  strong   constitution    can    -in 

that  would  kill  most  people,  but  the  Dumber  of  animals 

that  die  *ach  year  from  expo.- u re   to   tin    weather  is 
13 


194  ELEMENTS   OF   AGRICULTURE 

very  large,  and  many,  while  not  killed  outright,  are 
much  weakened  and  thus  made  liable  to  disease.  To 
obtain  the  best  results  from  feeding,  the  animal  must 
be  provided  with  some  protection  from  the  extremes 
of  heat  and  cold. 

Questions 

1.  In  what  does  the  art  of  feeding  consist?  2.  What  is 
necessary  besides  good  food  to  secure  success  in  feeding 
animals?  3.  In  what  kind  of  stables  should  animals  be 
kept?  4.  Why?  5.  What  effect  does  kind  treatment  have 
on  most  animals?  6.  What  effect  does  abuse  have  on  the 
value  of  an  animal?  7.  How  does  the  treatment  of  the  cow 
affect  the  amount  and  quality  of  the  milk?  8.  Why  is  it 
best  to  feed  and  attend  animals  with  regularity  and  system? 
9.  What  is  a  cow's  substitute  for  a  bath?  10.  Why  should 
animals  be  protected  from  the  weather? 


FEEDING   OF   ANIMALS  195 


CHAPTER  XXXVI.— Feeding  of  Animals 

190.  Methods  of  Feeding. — As  already  stated,  there 
are  several  method-  «>f  feeding  domestic  animals.  The 
animal  may  be  turned  out  to  Bad  its  own  living  from 
the  plants  growing  naturally  in  the  soil.  This  method 
of  feeding  is  known  as  pasturing.  Sometimes  the 
animal-  turned  out  to  pasture  are  supplied  in  winter 
or  in  very  dry  weather  with  extra  amounts  of  food  in 
the  shape  of  hay,  straw,  grain,  etc.  Another  method 
of  feeding  is  to  kecj>  the  animals  in  a  stahle  and  supply 
them  food  at  regular  intervals;  this  is  known  as  stall- 
i  i  I  pint.,  and  is  much  practiced.  The  art  of  feeding 
has  to  do  mainly  with  stall-feed ing,  for  when  the 
animal  it  at  pa-tun-  it,  as  a  rule,  finds  its  own  food. 
Now,  in  cither  method  of  feeding,  the  first  thing  to 
be 'looked  after  i-  water. 

191.  Water  for  Animals. — Domestic  animals  should 
always  be  furnished  an  ahundant  supply  of  fresh, 
pure  water.  Mo.-t  far:  I  ell  supplied  with  good 
water,  but,  unfortunately,  the  supply  provided  for 
animals  is  not  always  good.  The  stagnant  water  of 
ponds,  and  tin  f  polluted  streams  is  often  con- 
sidered good  enough  for  their  use.  All  don 
animals  prefer  pure  water,  and  if  they  drink  dirty  water 

mlt  bectnes  they  ran  gel  no  better.    Impure  water 

is  often  the  beginning  of  disease  in  animaK  and  from 
them  it  may  pass  to  human  beings.  The  milk  from 
cows  supplied  with  impure  water  often  causes  outbreaks 


196 


ELEMENTS    OF   AGRICULTURE 


of  disease  among  human  beings.    The  dairyman  cannot 
be  too  careful  about  the  water  he  provides  for  his  cows. 

192.  Pasturing. — Herbivorous  or  plant-eating  ani- 
mals in  their  native  state  make  their  living  off  the 
plants  growing  naturally  in  the  soil,  and  many  domestic 
animals  are  fed  in  this  way.  For  a  part  of  the  year 
at  least  they  are  turned  out  to  find  their  own  living 
from  the  grass  and  other  plants  which  form  their  food. 
This  is  the  method  generally  practiced  for  raising 
animals  that  are  to  serve  as  food  for  man.  In  raising 
cattle  for  market,  the  object  is  to  produce  the  greatest 
weight  of  flesh  at  the  least  possible  cost.  Where  the 
soil  will  grow  grasses  suitable  for  pasture,  large  tracts 
of  land  are  planted  in  grass,  which  furnishes  a  good' 
living  to  the  cattle  grazing  it.  The  labor  and  cost  of 
feeding  is  in  this  way  greatly  reduced,  and  the  profits 
resulting  from  the  sale  of  the  cattle  correspondingly 
increased.  The  bluegrass  regions  of  the  Eastern  States, 
and  the  great  prairie  regions  of  the  West,  supply 
pasture  for  many  herds  of  cattle.  Sheep  can  make  their 
living  on  rougher  and  poorer  fare  than  cattle,  and 
the  mountains,  while  often  too  poor  to  support  cattle, 
will  furnish  excellent  pasture  for  sheep. 

Even  the  best  of  pastures,  however,  can  supply  but 
a  scant  living  for  domestic  animals  in  winter,  and 
during  this  season  of  cold  other  food  in  some  shape 
should  be  provided  for  them.  During  cold  weather 
animals  require  a  constant  supply  of  proper  food  to 
keep  them  warm  If  not  fed  regularly,  their  store  of 
fat  is  all  used  up  to  maintain  the  proper  body  tem- 
perature, and  they  become  thin  and  weak,  and  unable 


FEEDING   OF  ANIMALS  197 

to  withstand  the  attacks  of  disease.  A  regular  supply 
of  food  better  enables  animals  to  endure  the  cold  and 
withstand  Hidden  changes  of  tempcrat Die.  An  animal 
irregularly  supplied  with  food  is  poorly  prepared  to 
meet  the  sudden  changes  in  our  climate.  In  a  half- 
d  condition  it  may  be  lubjeeted  to  the  cold  of 

a  blizzard,  and  suilVr  more  in  eOBSOquence  than  a  well- 
fed  animal.  To  obtain  healthy,  well-ejrown  animals  of 
any  kind,  I  constant  supply  61  good  food  is  necessary. 
Animals  may  either  be  left  out  all  the  year,  and  during 
the  winter  have  sxtll  food  supplied  them,  or  they  may 
be  stabled  and  fed  in  stalls.  If  left  in  the  pasture, 
some  sort  of  rough  shelter  should  be  provided  as  a 
protection  against  the  coldest  weather.  We  shall  con- 
sider the  subject  of  stall-feeding  in  the  following 
chapters. 

Questions 

1.  Name  several  methods  of  feeding  domestic  animals. 
2.  Why  is  it  Important  to  supply  domestic  animals  with 
pure  water?  3.  What  constitutes  the  food  of  herbivorous 
animals?  4.  What  is  meant  by  pasturing  animals?  5.  In 
raising  cattle  for  market  what  is  the  prime  object?  6.  Name 
a  part  of  this  country  where  large  herds  of  cattle  are  raised. 
7.  What  class  of  stock  can  make  their  living  on  a  poorer 
pasture  than  cattle?  8.  Why  should  animals  be  supplied 
with  extra  food  during  the  winter? 


198 


ELEMENTS    OF    AGRICULTURE 


CHAPTER  XXXVII.— Stock  Food 

193.  Need  for  Fixing  the  Amounts  of  Food  Supplied 
Animals. — In  stall-feeding  the  animal  must  be  sup- 
plied with  the  proper  amounts  of  food  to  keep  it  in 
good  condition.  How  are  we  to  know  just  how  much 
food  different  animals  require  to  keep  them  in  condi- 
tion ?  We  may  guess  at  the  proper  amounts,  or  we  may 
feed  the  animal  till  it  will  eat  no  more,  but  both  of 
these  methods  are  liable  to  cause  mistakes.  Animals 
are  greedy,  and,  if  allowed,  will  often  eat  more  than  is 
good  for  them.  So  it  is  best  to  know-  just  how  much 
food  to  give  them.  Now  there  is  a  method  of  deter- 
mining how  much  food  different  animals  require  to 
keep  them  in  condition.    Let  us  see  what  it  is. 

194.  Digestion. — Plants  from  the  elements  of  earth, 
air,  and  water  buiM  up  the  compounds  that  go  to 
form  them.  Animals  build  up  their  bodies  from  the 
compounds  formed  by  the  plants.  The  compounds  of 
the  plants  are  made  over  in  the  animal  body  into  other 
compounds,  and  the  process  is  called  digestion.  The 
process  of  digestion  is  a  very  complicated  one,  and  is 
not  thoroughly  understood;  so  we'  need  not  consider 
it  just  now.  It  is  enough  for  our  purpose  to  know 
that  animals  in  building  up  their  bodies  use  the  com- 
pounds formed  by  plants.  These  foods  are  taken  into 
the  animal's  stomach  where  portions  of  the  different 
compounds  are  digested,  which  means  that  they  become 


8TOCK    FOOD  199 

part  of  tin  animal's  body.  The  undigested  portion  is 
passed  off  as  manure. 

195.  Protein,  Non-Nitrogenous  Matter,  and  Mineral 
Matter  All  Necessary  Foods. — The  nitrogen  com- 
pounds of  animal  bodies  are  built  up  only  from  the 
QitlOgen  compounds  of  plants.  The  non-nitrogenous 
matters  eJ  animal  bodies  are  built  up  principally  from 
the  non-nitro^mous  matters  of  plants,  though  they 
may  slso  be  formed  from  the  nitrogen  compound-. 
The  mineral  matter  of  animal  bodies  comes  largely 
from  the  mineral  matter  of  plants.  Animals,  then,  in 
order  to  keep  their  bodies  built  up,  must  be  supplied 
with  food  containing  protein,  non-nitrogenous  matter, 
and  mineral  matter.  The  amount  of  mineral  matter 
required  in  animal  bodies  is  BO  small  that  there  is 
always  enough  in  the  ordinary  supply  of  food.      It    is 

not  necessary  to  consider  mineral  matter  as  i  f 1. 

Salt  is  not  considered  a  food,  hut  merely  a  relish. 
Protein  and  non-nitrogenous  matter  are  then  the  only 

solid  substances  re  need  consider  in  selecting  food  for 

animals.     Protein  builds  up  the  muscles,  nerve-,  blood. 

bones,  and  all  the  nit rogen-containing  parts  of  the 

body.  It  may  also  help  to  form  fat  ami  keep  the  body 
warm.    Protein  eompounds  ma\  build  up  e\rry 

pari  of  the  animal  body,  and  animal-  may  live  on  a 
food  made  up  excluah  ely  of  protein.  Bui  inch  a  diet  is 
hot  good  for  the  health  ol  most  domestic  animals*  N[on- 
nitrogenou>  matters  cannot  build  up  the  nitrogen  com- 
pounds of  animal  bodies,  ami  animals  star?e  t-»  death  on 
a  diet  of  non-nitrogenous  matter  alone.  But  certain 
amounts  of  non-nitrogenou-  m  necessary  Bot 


200 


ELEMENTS    OF    AGRICULTURE 


the  health  of  the  animal,  and  all  animal  food  should 
contain  some  of  these  compounds. 

196.  Composition  of  Foods. — We  have  already  learned 
that  plants  are  made  up  of  water  and  dry  matter,  and 
that  the  dry  matter  is  made  up  of  mineral  matter,  pro- 
tein, and  non-nitrogenous  matter..  In  order  to  deter- 
mine the  value  of  plants  for  cattle  foods,  the  amounts 
of  the  different  substances  they  contain  have  been 
determined.  In  determining  the  amounts  of  the  com- 
pounds,- the  plant  is  analyzed,  which  means  that  it  is 
broken  up  into  some  of  the  substances"  that  form  it. 
When  cattle  foods  are  analyzed,  they  are  divided  up 
into  six  classes  of  substances  as  follows: 

1.  Water  is  determined  by  drying  in  an  oven  a 
weighed  portion  of  the  finely  ground  substance  until  it 
is  perfectly  dry.  The  dried  portion  is  then  weighed, 
and  the  loss  in  weight  gives  the  amount  of  water,  or 
moisture  as  it  is  often  called. 

2.  Ash  is  determined  by  burning  at  a  low  heat  a 
weighed  portion  of  the  ground  substance.  The  weight 
of  the  ashes  gives  the  amount  of  mineral  matter  or  ash, 
usually  called  crude  ash. 

3.  Nitrogen  is  determined  by  a  process  that  is  too 
complicated  for  us  to  describe  here,  but  which  is  known 
to  be  accurate.  Protein  is  known  to  contain  about  16 
per  cent  of  nitrogen,  so  if  we  multiply  the  nitrogen 
found  by  6J  we  get  the  amount  of  protein  in  the  sub- 
stance.   The  protein  is  usually  called  crude  protein-. 

4.  Fats  and  oils  are  dissolved  from  a  weighed  por- 


STOCK    FOOD  201 

tion  of  the  ground  substance  by  means  of  ether.*  The 
ether  is  ersporafc  d.  and  the  fats  and  oil  are  weighed. 
The  result  is  usually  called  crude  fat. 

5.  The  woody  matter  it  determined  in  a  portion  of 
the  ground  substance  by  dissolving  out  all  the  other 
compounds  by  boiling  the  sample,  first  with  a  solution 
of  an  arid,  and  then  with  an  alkali.  The  woody  matter 
is  then  washed,  dried,  weighed,  burned,  and  the  weight 
of  ash  subtracted.     The  result  is  crude  fiber. 

The  per  cent  of  moisture,  crude  ash,  crude  pro- 
tein, crude  fat,  and  crude  fiber  are  all  added  together 
and   the  nun   Subtracted     from     100.     The     remainder 

reprceenta   irhei  ii  called    nitkogen-feee    extract. 

Nitrogen-free  extraci  is  so  called  because  it  contains 

DO  nitrogen  Compounds.    .It    is  made  ilp  principally  of 

Kerch,  sugar,  snd  gam,  hut  includes  everything  in  the 
plant  except  those  rabstancee  already  determined. 
An  snaljsifl  mads  in  the  manner  just  described  ii 

called  a    PBOXIMATB    ANALYSIS   of  I    feeding  stuff.      It 

Si  called  proximate  because  all  the  compounds  in  the 
rabstsneeare  neri  determined,  hut  onrjf  those  nucaaiij 

to  decide  its  value  si  I  cattle  food.  The  sum  of  the 
nutrient-  in  a  proximate  snaljsil  must  alua\>  make 
100. 

Different  cattle  (>»n\s  differ  greatlj  in  composition; 
some  contain  large  amounts  of  protein,  others  of  fat, 
and  still  others  of  starch.  Kven  the  same  food,  under 
different  conditions,  varies  in  composition.     A  great 

•Ether  la  a  liquid  much  used  In  medicine  to  produce  Insensibility  to 
pain  In  operations.  It  dissolves  f»u  and  oils  very  easily,  and  evaporatea 
very  quickly. 


202  ELEMENTS    OF    AGRICULTURE 

many  analyses  have  been  made  of  the  more  important 
feeding  stuffs,  and  the  average  of  all  the  analyses  of 
each  food  gives  its  average  composition.  Nearly 
everything  that  can  be  used  as  a  cattle  food  has  been 
analyzed,  and  the  results  recorded.  In  Table  V  of  the 
Appendix  are  arranged  the  averages  of  a  number  of 
analyses  of  the  more  important  feeding  stuffs.  These 
figures  are  intended  to  show  what  these  different  foods 
contain  under  average  conditions. 

197.  Nutrients. — The  various  compounds  in  plants 
that  are  useful  for  building  up  the  animal  body  are 
called  nutrients,  because  they  nourish  the  animal 
body.  The  nutrients  of  plants  are  protein,  and  non- 
nitrogenous  matters;  the  non-nitrogenous  matters  being 
divided  into  fat,  nitrogen-free  extract,  and  fiber. 

Questions 

1.  Why  is  it  best  to  know  exactly  how  much  food  stall- 
fed  animals  require  to  keep  them  in  good  condition? 
2.  How  do  animals  build  up  their  bodies?  3.  What  becomes 
of  the  food  the  animal  takes  into  its  body  in  eating?  4.  The 
change  that  food  undergoes  in  the  animal's  body  is  called 
what?  5.  How  are  the  nitrogen  compounds  in  animal  bodies 
built  up?  6.  How  is  the  non-nitrogenous  matter  of  animal 
bodies  built  up?  7.  Can  the  non-nitrogenous  matters  of 
plants  build  up  nitrogen  compounds  in  animal  bodies? 
8.  Can  the  nitrogen  compounds  of  plants  build  up  the  non- 
nitrogenous  matters  in  animal  bodies?  9.  What  is  meant 
by  an  analysis  of  a  food?  10.  How  is  the  amount  of  water 
determined  in  a  food?  11.  How  is  ash  determined?  12.  How 
is  protein  determined  from  nitrogen?  13.  How  is  fat  deter- 
mined? 14.  How  is  woody  matter  determined?  15.  What  is 
meant  by  nitrogen-free  extract,  and  how  is  it  determined? 
16.  What  is  a  proximate  analysis?    17.  What  are  nutrients? 


8TOOK    FOOD  203 

PROBLEM 

Suppose  a  sample  of  hay  contains  9.77  per  cent  of  water, 
8.99  per  cent  of  protein,  1.75  per  cent  of  fat,  31.05  per  cent 
of  fiber  and  4.55  per  cent  of  ash.  How  much  nitrogen-free 
extract  does  the  hay  contain? 


204  ELEMENTS   OF  AGRICULTURE 


CHAPTER    XXXVIIL— Digestibility    of    Stock 
.  Foods 

198.  The  Value  of  a  Food  Depends  on  Its  Digesti- 
bility.— Only  a  part  of  the  food  eaten  by  animals  is 
digested;  the  undigested  portion  is  passed  off  as  manure. 
Naturally,  the  portion  digested  is  of  much  greater 
value  to  the  animal  body  than  the  undigested  portion. 
So  in  judging  of  the  value  of  a  cattle  food,  we  must 
always  take  into  consideration  the  digestibility  of  the 
nutrients  contained  in  the  food.  Table  V  of  the 
Appendix  shows  the  results  of  a  number  of  analyses 
of  different  foods,  most  of  which  are  very  different  in 
composition.  These  foods  also  differ  very  much  in 
the  amounts  of  digestible  nutrients  they  contain.  Let 
us  see  how  it  is  possible  to  determine  the  digestibility 
of  the  nutrients  of  cattle  foods. 

199.  Digestion  Experiment.— Of  the  food  eaten  by- 
animals,  a  part  is  digested  and  retained  in  the  body, 
and  a  part  passed  off  as  manure.  Now,  suppose  we 
feed  to  an  animal  a  weighed  portion  of  food  in  which 
we  have  determined  accurately  the  amounts  of  the 
various  nutrients.  If  no  other  food  has  been  given  the 
animal,  we  can  collect  the  manure  resulting  and  in  it 
determine  the  amounts  of  the  nutrients  undigested. 
The  difference  between  the  total  nutrients  in  the  food 
and  the  undigested  nutrients  in  the  manure  will  give 
us  the  digestible  nutrients.  Suppose  we  select  an  ox 
and  feed  him  30  pounds  of  hay  per  day.    The  hay  con- 


DIGESTIBILITY    OF   STOCK    FOODS  205 

tains  0   pel  rent  of  protein.     Bo   we  ITS  BUpplying  the 

ta  is  poundi  of.protein  perdty,    li'  the  manure  from 

the  «>\  contain  •"»  pax  cent  of  protein,  only  one-half  or 

i  .in  o|  the  protein  of  the  baj  Itible.    In 

a*e  may  determine  tin-  digestibility  of  the 

other  nutrients   of   the    food.      Sneh   tests  of   food-   II 

these  are  called  digestion  experiments. 

In  making  digestion  experiments  much  care  and 
patience  are  required.  For  use  in  such  tests  only 
healthy  average  animals  should  be  selected,  and  for  a 
few  days  before  the  beginning  of  the  experiment  the 
animal  must  be  fed  nothing  but  the  food  to  be  tested. 
In  this  time  the  manure  resulting  from  any  other  food 
eaten  previously  by  the  animal  is  passed  from  the  body. 

Digestion  experiments  are  usually  continued  for 
several  days  or  even  week-,  and  during  the  time  they 
are  in  progress  the  animal  must  be  carefully  looked 
Samples  of  the  food  to  be  tested  must  be  care- 
fully analyzed  to  determine  the  amounts  of  its 
nutrients;  and  at  certain  intervals  the  animal  must  he 
supplied  with  weighed  quantities  of  the  food.  All  the 
manure,  both  liquid  and  solid,  passed  by  the  animal 
during  the  experiment  should  be  collected  and  weighed. 
Samples  of  the  manure  are  analyzed  in  order  to  deter- 
mine the  amountl  of  the  nutrients  left  in  it;  a  number 
of  samples  being  taken,  each  at  a  different  >tage  of  the 
experiment.  The  average  amounts  of  the  nutrients  in 
the  manure  arc  subtracted  from  the  average  amounts 
of  the  same  nutrients  in  the  .food,  and  the  results  show 
the  amounts  of  digested  nutrients.  With  figures 
determined  in  this  way  we  may  easily  calculate  the 


206  ELEMENTS    OF   AGRICULTURE 

digestible  nutrients  in  any  given  weight  of  food.  For 
"instance,  from  the  composition  of  timothy  hay  shown 
in  Table  V  in  the  Appendix  we  learn  that  every  100 
pounds  of  such  hay  contains  5.9  pounds  of  protein,  2.5 
pounds  of  fat,  45  pounds  of  nitrogen-free  extract,  and 
29  pounds  of  fiber.  Digestion  experiments  show  that 
48  per  cent  of  the  protein,  57  per  cent  of  the  fat,  63 
per  cent  of  the  nitrogen-free  extract,  and  52  per  cent 
of  the  fiber  are  digestible.  Then  every  hundred  pounds 
of  timothy  hay  must,  according  to  these  figures,  contain 
the  following  amounts  of  digestible  nutrients:  2.8 
pounds  of  protein,  1.4  pounds  of  fat,  28.4  pounds  of 
nitrogen-free  extract  and  15  pounds  of  fiber. 

A  great  many  digestion  experiments  have  been  made 
with  many  different  kinds  of  animals  and  foods.  Such 
tests  are  necessary,  for  different  animals  have  different 
powers  of  digestion.  A  cow,  for  instance,  may  digest 
more  of  a  certain  kind  of  food  than  a  horse,  a  growing 
calf  may  digest  more  of  a  food  than  an  old  steer.  Dif- 
ferent samples  of  the  same  food  differ  in  the  amounts 
of  digestible  nutrients  they  contain.  It  is  only  by 
making  many  tests,  and  taking  their  average  that 
reliable  figures  can  be  obtained.  The  experiment 
stations  of  this  and  of  other  countries  have  made,  and 
are  making,  many  tests  to  determine  the  digestibility 
of  all  kinds  of  animal  foods,  and  in  Table  VI  of  the 
Appendix  will  be  found  the  averages  of  the  most 
reliable  of  these  tests  for  the  foods  shown  in  Table  V. 
The  figures  giving  the  percentages  of  the  nutrients 
digested  are  called  digestion  coefficients.  With 
the  figures  in  Tables  V  and  VI  one  may  easily  calculate 


DIGESTIBILITY    OF    8TOCK    POODS  207 

the  amounts  of  digestible  nutrients  in  any  of  the  foods 
there  recorded.  For  the  convenience  of  the  student  we 
have  calculated  the  amounts  of  digestible  nutrient-  in 
most  of  the  foods  shown  in  Table  V,  and  the  results 
are  arranged  in  Table  VII.  The  nitrogen-free  extract 
and  crude  fiber  are  combined  in  this  tabic,  and  the 
sum  is  given  under  carbohydrate*. 

Questions 

1.  On  what  does  the  value- of  a  cattle  food  chiefly  depend? 
2.  In  Judging  of  the  value  of  a  cattle  food  what  must  be 
considered  besides  its  composition?  3.  How  may  the 
amounts  of  digestible  nutrients  in  a  food  be  determined? 
4.  What  are  digestion  coefficients? 

PROBLEMS 

1.  Suppose  we  feed  a  horse  40  pounds  of  corn  which  con- 
tain 4  pounds  of  protein,  and  the  manure  resulting  contains 

1  pound  of  protein,  what  per  cent  of  the  protein  is  digestible  7 

2.  Suppose  a  cow  is  fed  30  pounds  of  clover  hay,  which 
contain  3  pounds  of  protein,  and  the  manure  resulting  con- 
tains .96  of  a  pound  of  protein,  what  per  cent  of  the  protein 
is  digestible? 

3.  Suppose  a  steer  is  fed  30  pounds  of  ensilage  containing 

2  pounds  of  crude  fiber,  and  the  manure  resulting  contains 
.76  of  a  pound  of  crude  fiber,  what  per  cent  of  the  fiber  is 
digestible? 


208 


ELEMENTS    OF    AGRICULTURE 


CHAPTEE    XXXIX.— Calculating    Rations    for 
Animals 

200.  Rations. — The  iood  supplied  an  animal  during 
any  stated  period  is  called  a  ration;  thus  the  food  of 
one  day  is  called  a  day's  ration.  Calculating  the  differ- 
ent amounts  of  the  food  to  be  included  in  a  ration  is 
called  compounding  rations.  The  compounding  of 
rations  means  the  mixing  of  the  proper  amounts  of 
digestible  nutrients  to  keep  the  animal  in  good  con- 
dition. 

201.  Feeding  Tests. — Different  animals  require  dif- 
ferent amounts  of  digestible  nutrients,  and  the  same 
animal  under  different  conditions  requires  different 
amounts.  After  a  long  walk  we  usually  come  home 
hungry;  we  need  food  to  renew  the  portions  of  our 
body  worn  by  the  exercise  of  walking.  The  question 
is  how  much  food  is  needed.  "We  usually  settle  the 
question  by  eating  till  we  are  no  longer  hungry,  and 
by  this  method  eat  too  much,  and  make  ourselves  sick. 
Animals,  too,  if  allowed  the  opportunity  will  oft^n 
make  themselves  sick  by  overeating.  Allow  a  horse 
to  help  himself  from  an  oat  or  corn  bin,  and  he  will  eat 
till  he  can  hold  no  more;  this  usually  results  in  a  case 
of  colic.  To  keep  stall-fed  animals  in  good  condition, 
they  must  be  supplied  with  the  proper  amounts  of 
nutrients,  and  no  more.  To  overfeed  an  animal  is  as 
bad  as  to  underfeed  it.  In  order  to  determine  how  much 
food  different  animals  require,  a  great  many  careful 


CAi'  G    BA3T09M    PQft    a  m  ".  \i>  '_'"'.> 

tests  have  been  made.  Many  different  kinds  of  animals 
in  rarious  parti  oi  the  world  hare  been  fed  weighed 
amounts  of  food,  in  samples  of  whicli  the  digestible 
nutrients  had  been  previously  determined.  In  this 
manner  the  weight-  <h*  digestible  protein  ami  dob- 
nltrogenoiifl  matters  nee  isary  to  keep  the  animal  in 
i  ondition  ;ire  determined.  Such  figures  are  called 
ir.i:!)i.\<;  standards.  In  Table  \'lll  of  the  Appendix 
the  average  results  of  many  such  testa  are  recorded. 

202.  Nutritive  Ratio.— The  last  column.  Table  VIII. 
shows  Dutritive  ratios.  By  nutritive  ratio  is  meant 
the  proportion  of  digestible  protein  to  fat,  nitrogen-free 
extract  ami  fiber  combined.  To  calculate  the  ratio  we 
must  Btarl  by  multiplying  the  fat  by  2.4;  for  the  Eat 
is  considered  nearly  ''\  times  si  valuable  for  food  as  the 
carbohydrates  (nitrogen-free  extract  ami  crude  fiber). 
Lei  as  take  as  an  example  the  corn  fodder  shown  at 
the  beginning  of  Table  Vl  I.  We  have  .1  of  a  pound 
of  fat  x  2.4  =  .90  +  11.6  carbohydrates :  18.56  -^  1 
of  protein  =  12.56,  giving  a  ratio  of  1  to  12.5G,  which 
means  that  the  food  contains  12.50  times  as  much 
carbohydrates  ami  fat  as  protein.  We  have  the  follow 
formula: 

Fat  X  2  4  -f  carbohydrate* 


Protein 


nutritivi*  ratio. 


203.  Compounding  Rations. — Xow  let  us  see  how  the 
figures  in  Table  VI II  may  he  applied.  Suppose  we  have 
a  horse  doing  ordinary  farm  work,  and  we  wish  to  sup- 
ply him  with  the  proper  amount  of  food  to  enable  him 
to  do  his  work  well  and  at  the  same  time  keep  him  in 
H 


210 


ELEMENTS    OF    AGRICULTURE 


good  condition.  Our  horse  weighs  between  950  and 
1,000  pounds,  and  we  have  a  supply  of  oats,  shelled 
corn,  and  clover  hay,  with  which  to  feed  him.  How 
can  we  mix  these  foods  so  as  to  supply  him  the  proper 
amounts  of  protein,  fat  and  carbohydrates  ?  By  refer- 
ring to  Table  VIII  we  find  that  a  horse  at  moderate 
work,  for  every  thousand  pounds  of  live  weight  requires 
each  day  22  pounds  of  dry  matter,  containing  of  diges- 
tible nutrients,  1.8  pounds  of  protein,  .6  of  a  pound 
of  fat  and  11  pounds  of  carbohydrates;  giving  a  nutri- 
tive ratio  of  1  to  6.9.  In  mixing  our  foods  to  supply 
this  ratio  we  will  start  by  taking  10  pounds  of  corn. 
Referring  to  Table  VII  we  find  that  this  amount  of 
corn  contains  8.9  pounds  of  dry  matter,  .8  of  a  pound 
of  digestible  protein,  .46  of  a  pound  of  digestible  fat, 
and  6.59  pounds  of  digestible  carbohydrates.  Next  we 
take  10  pounds  of  clover  ha}^,  which  we  find  from  the 
same  table  contains  8.47  pounds  of  dry  matter;  and  of 
digestible  nutrients,  .76  of  a  pound  of  protein,  .20  of  a 
pound  of  fat,  and  3.84  pounds  of  carbohydrates. 
Adding  these  figures  together  we  have  17.4  pounds  of 
dry  matter,  1.6  pounds  of  protein,  .66  of  a  pound  of  fat, 
and  10.4  pounds  of  carbohydrates.  To  complete  our 
required  ration  we  need  only  4.6  pounds  of  dry  matter; 
therefore  10  pounds  of  oats  would  give  more  than  is 
needed,  so  we  will  take  5  pounds.  This  amount  of  oats 
according  to  Table  VII  gives  us  4.45  pounds  of  dry 
matter;  and  of  digestible  nutrients,  .46  of  a  pound  of 
protein,  .21  of  a  pound  of  fat,  and  2.36  pounds  of 
carbohydrates.  Adding  these  figures  to  those  for  hay 
and  corn  we  have: 


CALCULATING    RATIONS    FOE    ANIMALS  211 

Digestible  Nutrients. 

Dry  Carbo- 

Matter.  Protein.  Kat.  hydrates. 

10    p«»u  in  Is   shelled   corn...       8.9  .80  .46  6.59 

10  pounds  clover  hay 8.5  .76  .20  3.84 

5  pounds  oats  4.5  .46  .21  2.36 

Compounded  ration   21.9  *    .87  12.79 

Required  ration  22.0  1.80  .60  11.00 

Nutritive  ratio  in  compounded  ration,  1  to  7.3;  required 
ratio,  1  to  6.9. 

These  rations  agree  well  enough,  so  let  us  try 
another,  say  one  for  a  cow  giving  milk.  Table  VIII 
shows  that  a  cow  giving  milk,  for  every  thousand 
j x minis  of  weight  requires  per  day  28  pounds  of  dry 
matter  containing  of  digestible  nutrients,  2.5  pounds 
protein,  .5  pound  fat,  ami  12  pounds  carbohydrates. 
But  suppose  our  cow  weighs  only  800  'pounds.  Wc 
should  then  take  only  .S  of  the  ration  or  22.4  pounds 
dry  matter,  2  pounds  protein,  .4  pound  of  fat,  and  9.G 
pounds  carbohydrates,  w  e  have,  to  feed  our  cow,  corn 
ensilage,  COWpea  hay,  hay  of  mixed  grasses,  and  wheat 
bran.  As  ensilage  is  a  bulky  food  containing  much 
water,  let  us  start  by  taking  30  pounds  of  it,  and  as 
bran  is  a  rich  dry  food,  we  should  take  much  less  of  it, 
say  5  pounds.  The  amounts  of  these  two  foods  together 
Dj  about  1<>  pounds  of  dry  matter,  leaving  about 
LS  pound-  to  be  Supplied  by  th€  tWO  hays.     As  ensilage 

contains  but  little  protein  let  dj  take  the  larger  amount 
of  pes  hay  which  ifl  rich  in  protein.  We  will  take  say 
8  ponndl  of  the  pea  hay  and  .">  pounds  of  the  mixed  hay. 
Now  referring  to  Table  \  II  we  find  that  the  amounts 
of  food  selected  give  the  following  figures: 


212  ELEMENTS    OF    AGRICULTURE 

Digestible  Nutrients. 

Dry  Carbo- 

Matter.     Protein.  Fat.  hydrates. 

30  pounds  of  ensilage 6.27  .27  .21  3.39 

5  pounds  of  bran 4.40  .61  .13  1.96 

8  pounds  of  pea  hay 7.14  .86  .08  3.12 

5  pounds  of  mixed  hay....    ^35  .30  .06  2.05 

Compounded  ration   22.16  2.04  .48  10.52 

Required  ration  22.40  2.00  .40  9.60 

Nutritive  ratio  in  compounded  ration,  1  to  5.7;  required 
ratio,  1  to  5.3. 

It  is  not  necessary  that  the  calculated  ration  should 
agree  exactly  with  the  standard.  The  agreement  be- 
tween the  standard  and  the  two  examples  given  is 
close  enough  for  all  practical  purposes.  The  standards 
in  Table  VIII  are  intended  merely  as  guides  in  mixing 
rations,  not  as  fixed  rules  by  which  we  must  work.  In 
calculating  rations,  find  the  amounts  of  digestible 
nutrients  in  the  principal  food  to  be  used,  and  try 
combining  with  these  figures  those  for  varying  amounts 
of  the  other  foods  till  a  ration  is  obtained  giving  a 
nutritive  ratio  as  near  as  possible  to  the  standard.  It 
is  not  necessary  to  use  fractions  of  pounds  in  weighing 
the  different  foods. 

204.  Weighing  the  Different  Foods  in  the  Ration. — 
It  would  of  course  require,  far  too  much  labor  to  weigh 
out  the'  different  foods  each  time  an  animal  is  fed,  and 
such  care  is  not  necessary.  Grains,  meals,  bran,  and 
other  similar  -foods  may  be  measured,  and  the  weight 
of  a  given  measure  determined.  Ensilage  may  also  be 
measured,  and  so  may  root  crops.  For  hay  and  other 
fodders  the  weights  of  the, fodder  held  on  a  certain 


CALCULATING   RATIONS   FOB  ANIMALS  213 

fork  or  in  a  hamper  should  be  determined  once  for  all. 

With    this    knowledge    the    weight  of  fodder  may  be 

j     estimated    without    actual    weighing  at  each 

feeding. 

Questions 

1.  What  is  meant  by  a  ration?  2.  What  is  meant  by  nu- 
tritive ratio?  3.  What  are  feeding  standards?  4.  How  are 
feeding  standards  determined? 

PROBLEMS 

1  We  wish  to  mix  a  ration  for  a  fattening  ox  weighing 
1,000  pounds,  and  for  food  have  decided  to  use  30  pounds 
corn  ensilage,  5  pounds  cottonseed-meal  and  5  pounds  mixed 
hay.  How  much  wheat  straw  must  be  added  to  complete  the 
ration? 

2.  Suppose  we  have  a  herd  of  wool-growing  sheep  and 
wish  to  feed  them  during  the  winter.  Our  sheep  weigh 
about  130  pounds  each,  so  that  eight  sheep  weigh  about 
1,000  pounds.  The  food  we  have  to  give  them  consists  of 
shelled  corn  and  mixed  hay.  Calculate  the  amount  of  each 
food  necessary  to  supply  the  proper  ration. 

3.  Calculate  the  nutritive  ratio  in  a  ration  supplying  2.3 
pounds  of  protein,  .88  pound  fat  and  14  pounds  carbohy- 
drates. 


214  ELEMENTS    OF   AGRICULTURE 


CHAPTER  XL.— Selecting  Stock  Foods 

205.  Different  Animals  Require  Different  Foods. — 
The  art  of  stock  feeding  does  not  consist  simply  in 
mixing  certain  proportions  of  digestible  nutrients.  The 
ration  may  contain  the  proper  proportions  of  digestible 
nutrients,  and  yet  be  unfit  for  food.  The  taste  of  the 
animal  fed  must  be  considered.  Different  kinds  of 
animals  differ  in  their  tastes  for  foods  much  as  human 
beings  do.  The  cow  eats  readily  food  that  a  horse  will 
not  touch,  and  the  pig  eats  food  that  would  be  refused 
by  either  the  cow  or  horse.  The  art  of  stock  feeding 
consists  in  supplying  animals  not  only  the  proper 
amounts  of  food,  but  also  the  proper  kinds  of  food  as 
well. 

206.  Volume  of  Food. — Besides  the  digestible  por- 
tions of  the  food,  all  animals  require  a  certain  volume 
of  indigestible  food.  Nature  has  provided  that  they 
digest  only  a  part  of  their  food,  and  pass  the  undigested 
portion  off  as  manure.  It  is  possible  to  feed  animals 
with  certain  foods  all  of  which  they  can  digest,  and  vet 
find  that  they  do  not  do  well  on  such  a  ration.  Such 
foods  are  soon  digested,  leaving  the  stomach  and  intes- 
tines practically  empty,  and  this  condition  of  things  is 
not  good  for  the  animal.  Cattle,  especially,  require 
large  amounts  of  food,  as  their  stomachs  are  very  large. 
The  stomach  of  an  ox  is  divided  into  four  compart- 
ments, all  of  which  together  hold  about  250  quarts. 
The  stomach  of  the  horse  is  much  smaller,  holding 


SELECTING  STOCK  FOODS  215 

only  17  to  19  quarts;  and  the  stomach  of  the  hog  holds 
only  7  to  9  quarts.  The  first  compartment  of  the 
stomach  in  cattle  serves  as  a  sort  of  storehouse  for 
food  when  first  swallowed.  Cattle,  after  chewing  and 
■wallowing  their  food,  bring  it  back  into  the  mouth 
from  this  first  stomach,  and  after  chewing  it  again, 
swallow  it.  This  process  is  called  chewing  the  cud. 
Sheep  as  well  as  cattle  chew  the  cud,  but  the  horse  and 
pig  do  not. 

207.  All  the  Foods  Produced  on  the  Farm  May  Be 
Utilized. — The  fact  that  different  domestic  animals 
prefer  different  kinds  of  food  enables  the  careful  stock 
man  to  use  to  advantage  all  the  food  produced  on  his 
farm.  Cattle  eat  coarse  fodder  that  horses  will  not 
touch,  and  hogs  eat  many  foods  unfit  for  either  horses 
or  cat tlf.     Every  pound  of  food  produced  may  be  used 

<>ck  of  some  kind.  The  coarsest  fodder,  if  properly 
prepared,  i>  readily  eaten  by  cattle;  and  wheat  straw, 
l  pour  fond  in  it-ell*  i>  useful  for  mixing  with  rich  foods 
such  as  wheat  bran  or  OOttoneeed-meal  Vrrv  coarse 
fodder  should  he  run  through  a  shredding  machine 
before  it  i>  fed  A  ihredding  machine  lean  the  fodder 
into  bite,  in  which  condition  it  is  more  palatable  to  the 
animal.     It   if  well  to  dampen  very  dry   fodder  before 

Og,  both  to  render  it  more  palatable  and  to  y 

(he  dual  from  it  entering  the  noee  and  lungs  of  the 
animal  to  which  it  is  fed.     Many  horses  contract  had 

coughs  from  the  dust  rising  from  wry  drv  fodder. 

208.  Experience  and  Observation  Necessary. — The 
feeding  standards  in  Tahle  Y 1 1 1  are  intended  merely 
as  guides  for  mixing  the  different  foods  that  make  up 


216  ELEMENTS    OF    AGRICULTURE 

the  ration.  The  kinds  of  food  that  make  up  the  ration 
are  determined  according  to  the  judgment  of  the  person 
doing  the  feeding.  Observation  and  experience  are  the. 
best  guides  for  selecting  the  proper  foods,  and  every 
stock  grower  should,  for  his  own  satisfaction,  try  all 
the  different  stock  foods  within  his  reach.  By  keeping 
a  record  of  each,  he  can  determine  which  are  best  for 
his  purpose.  It  is  a  bad  plan  to  depend  on  only  two  or 
three  foods;  all  animals  like  a  variety  of  food,  and  if 
fed  the  same  thing  day  after  day  they  in  time  tire  of  it 
and  lose  their  appetite. 

209.  Cost  of  Foods. — Foods  costing  the.  most  money 
are  not  always  the  best,  nor  are  the  foods  costing  the 
least  money  always  the  cheapest.  The  author  hud 
occasion  a  few  37ears  ago  to  make  analyses  of  many 
kinds  of  stock  foods,  and  the  results  of  a  few  of  these 
analyses  may  serve  as  examples : 

From  a  certain   town  a  sample  of    food   known   as 

" 's  Food  for  Stock  and  Poultry"  was  obtained. 

An  analysis  showed  that  this  food  contained  in  every 
hundred  pounds,  approximately,  16  pounds  of  protein, 
7J  pounds  of  fat  and  GO  pounds  of  carbohydrates.  An 
examination  showed  that  the  food  consisted  of  wheat 
bran  and  corn-meal,  with  the  addition  of  a  little  cotton- 
seed-meal. To  the  food  had  been  added  a  strong-smell- 
ing powder  called  fenugreek,  which  is  of  no  value  either 
as  a  food  or  medicine.  This  stock  food  sold  at  6  cents 
a  pound  or  $120  a  ton.  From  the  same  town,  another 
sample  of  stock  food,  known  as  a  mixed  cattle  food,  was 
obtained.  This  food  was  also  made  up  of  wheat  bran, 
corn-meal,  and  cottonseed-meal,  but  contained  no  fenu- 


8EU  '    I  <>DS  217 

An  analysis  showed  that  every  hundred  pounds 
contained,  approximately,  L7|    pounds  of  protein,  G 

ponndf  "I'  tat  .ind  82J  pounds  <>|'  carbohydrates.  This 
lold  for  $tf  a  t<»n,  and  contained  more  nutrients 
than  the  food  sold  at  $120.  The  digestibility  of  the  two 
foods  was  practically  the  same.  Persons  buying  the 
expensive  food  were  paying  $103  extra  for  the  addition 
of  a  little  worthless  fenugreek.  There  are  many  so- 
called  prepared  stock  foods  on  the  market,  and  for  the 
most  part  they  are  not  worth  the  prices  charged  for 
them.  In  buying  any  sort  of  prepared  food  or  mill 
product,  if  there  is  any  doubt  as  to  the  quality,  a  sample 
should  be  sent  to  the  nearest  chemist  for  analysis. 

Questions 

1.  In  mixing  a  ration  what  other  things  besides  the 
nmount  cf  digestible  nutrients  must  be  considered?  2.  Why 
is  it  important  to  supply  animals  food  containing  indigesti- 
ble as  well  as  digestible  compounds?  3.  About  how  many 
quarts  does  the  stomach  of  an  ox  hold?  4.  What  is  the 
capacity  of  the  horse's  stomach?  5.  How  is  the  stomach  cf 
the  ox  divided  up?  6.  What  is  the  purpose  of  the  first 
stom.uh  of  the  ox?  7.  What  is  meant  by  chewing  the  cud? 
S.  low  13  it  possible  to  utilize  all  the  food  products  on  the 
f:irni?  9.  Why  i3  it  advisable  to  try  many  different  kinds 
of  food  in  foeding  animals?  10.  Of  what  value  are  most 
prepared   stock   foods? 


218 


ELEMENTS    OF   AGRICULTURE 


PART    VII.— Miscellaneous  Topics 


CHAPTER  XLL— Birds 

210.  Destruction  of  Birds. — In  this  age  of  ours  a 
money  value  is  the  standard  by  which  most  things  are 
judged.  The  first  question  is  usually,  "  What  is  it 
worth  ?  "  Now,  what  are  birds  worth  ?  They  are  pretty : 
many  of  them  sing,  and  most  kindly  disposed  persons 
enjoy  seeing  them  about,  but  have  they  an  actual 
money  value?  This  question  has  been  answered  time 
and  again,  and  the  answer  is  always  the  same.  Birds 
are  of  value,  and  they  are  of  value  to  every  living 
creature  on  this  earth.  It  is  not  simply  the  birds  that 
supply  food  for  man  and  beast  that  are  of  value,  but 
those  pretty,  bright  little  things  that  come  each  spring 
to  enliven  our  country — robins,  blackbirds,  redbirds, 
orioles,  swallows,  and  a  host  of  others.  Every  year  they 
come  with  the  spring,  and  many  of  them  spend  their 
summer  with  \is,  but  not  as  welcome  guests.  They  are 
greeted  with  guns,  sling-shots,  traps,  stones,  hunted  by 
cats  and  dogs,  robbed  of  their  nests  and  eggs,  perse- 
cuted by  man  and  beast.  Those  unfortunates  with 
bright,  pretty  feathers  are  killed  that  they  may  serve,  to 
ornament  women's  heads.  We  laugh  at  the  poor  Indian 
who  decks  himself  with  paint  and  feathers  for  some 
festive  occasion;  but  each  year  thousands  upon  thou- 
sands of  beautiful  and  useful  birds  are  killed  in  order 
that  women  may  adorn  their  heads,  not  with  feathers 


BUM  219 

only,  but  with  whole  birds,  copying  the  fashion  of  tho 
painted  tsrsge  whom  they  scorn.  Main  thousands  too 
die  each  year  by  the  hands  of  so-called  sportsmen;  not 
game  birds  merely — such  as  turkeys,  geese,  duck,  and 
partridges — but  robins,  larks,  doves,  night  hawks  (bull- 
bats),  martin-,  ami  many  other  useful  birds.  To  the 
average  man  with  a  gun  everything  with  feathers  is  a 
game  bird,  ami  he  slaughters  without  mercy.  To  the 
small  boy  the  destruction  of  birds  ami  their  nest-  is  a 
failing  source  of  delight,  ami  the  murder  <>f  many 
helpless  birdl  a  thing  to  boast  of.  lie  kills  merely  for 
the  love  of  killing,  gratifying  his  hrnte  instincts  by 
putting  to  (hath  creatures  too  weak  to  defend  them- 
selves against  attack.  Men.  women,  ami  children  arc 
United  with  animals  in  a  war  on  birds.  Animals  kill 
for  food;  men  and  children  mainly  for  the  love  of  kill- 
in-,  v,  anas  to  Satisfy  their  vanity.     It  would  xrm  that 

in  this  .asc  the  beasts  an-  endowed  with  higher  motives 

than   nun   and   women. 

211.  Value  of  Birds.—  But  you  say.  hird<  steal  fruit, 
they  injure  grain  crops,  some  of  them  kill  chickens, 
and  what  use  are  i  hey  anyway  ?  Did  you  cwrseea  tree 
stripped  of  its  leaves  by  caterpillars  or  other  insects? 
Did  you  erer  Bee  a  line  fruit  orchard  dead  or  dying  as 
though  swept  by  a  lire?  Did  you  .\er  see  a  field  of 
grain  or  grass  eaten  by  an  army  of  worms?  Did  you 
•ae  a  garden  destroyed  by  worms  or  insects?  Such 
thin--  happen  every  year,  and  are  becoming  mon 

more  common.    Steal  amiss  <>f  insects  are  bos] 

!« starting  .crops,  trees,  grass,  an  I  -»reen 

thing.    The  birds  ure  busy  destroying  the  s,  and 


220  ELfcHE&fS    Of   AGRICULTURE 

man  is  busy  destroying  the  birds.  Which  is  to  succeed  ? 
If  man  succeeds,  the  insects  will  be  left  in  peace  to 
grow  and  multiply,  and  the  destruction  of  all  plant  life 
will  certainly  follow.  Chapman  gives  us  an  admirable 
description  of  how  birds  are  constantly  busy  destroying 
insects :  "  Consider  for  a  moment/'  he  writes,  "  what 
the  birds  are  doing  for  us  in  summer  when  the  hum  of 
insect  life  fills  and  becomes  almost  an  inherent  part 
of  the  atmosphere. 

"  In  the  air,  swallows  and  swifts  are  coursing  rapidly 
to  and  fro,  ever  in  pursuit  of  the  insects  which  consti- 
tute their  sole  food.  When  they  retire  the  nighthawks 
and  whippoorwills  will  take  up  the  chase,  catching 
moths  and  other  nocturnal  insects  which  would  escape 
day-flying  birds.  The  flycatchers  lie  in  wait,  darting 
from  ambush  at  passing  prey,  and  with  a  suggestive 
click  of  the  bill  returning  to  their  post.  The  warblers, 
light,  active  creatures,  flutter  about  the  terminal 
foliage,  and,  with  almost  the  skill  of  a  humming-bird, 
pick  insects  from  leaf  or  blossom.  The  vireos  patiently 
explore  the  undersides  of  leaves  and  odd  nooks  and 
corners  to  see  that  no  skulker  escapes.  The  wood- 
peckers, nuthatches,  and  creepers  attend  to  the  tree 
trunks  and  limbs,  examining  carefully  each  inch  of 
bark  for  insects'  eggs  and  larvae,  or  excavating  for  the 
ants  and  borers  they  hear  at  work  within.  On  the  ground 
the  hunt  is  continued  by  thrushes,  sparrows,  and  other 
birds  who  feed  upon  the  innumerable  forms  of  terres- 
trial insects.  Few  places  in  which  insects  exist  are  neg- 
lected; even  some  species  which  pass  their  earlier  stages 


IIIKDS 


821 


or  entire  lives  in  the  water  are  preyed  upon  by  aquatic 
beds."* 

But  birda  ;nv  asefn]  in  other  ways  besides  destroying 
harmful  Inflects.  There  ere  many  kinds  of  birds  that 
live  principally  on  fche  Bead  of  weed-,  and  bo  this  way 
►j  -rrai  numbers  oi  weeds  which  would  other- 
wise grow  up  to  the  hurt  of  fanners.  Then  there  are 
still  other  kinds  that   make  their  living  on  field  mice, 

rats,  larger  insects — grasshoppers,  etc  Lei  as  consider 
the  work  done  by  each  of  these  classes  of  birds,  begin- 
ning with  the  insect-eater,  or  insectivorous  bird. 

Questions 

1.  How  are  birds  received  when  they  come  in  the  spring? 
2.  What  harm  do  birds  do?  3.  What  good  do  they  do? 
4.  into  what  groups  are  birds  divided?  5.  What  are  insecti- 
vorous birds? 

iK>rt  of  Conn.  3o»rd  of  Agr.,  law,  p.  76. 


222  ELEMENTS    OF    AGRICULTURE 


CHAPTER  XLIL— Insectivorous  Birds 

212.  Damage  Done  by  Insects. — Before  taking  up 
insectivorous  birds,  let  us  try  to  get  some  idea  of  the 
damage  done  to  farm  crops  each  year  by  insects. 

Harmful  insects  feed  mainly  on  the  young  and  tender 
foliage  of  growing  plants,  but  they  also  attack  the  seed, 
fruit,  stem,  and  roots.  In  fact  every  portion  of  the 
plant  is  used  as  food  by  various  insects,  and  no  plant  is 
safe  from  their  attacks.  Of  course,  not  all  insects  are 
harmful.  There  are  insects  that  prey  on  injurious 
insects,  but,  unfortunately,  the  harmful  insects  far  out- 
number the  beneficial  kinds.  Birds  prey  largely  on  the 
injurious  kinds. 

A  careful  estimate  places  the  average  damage  done 
annually  by  insects  in  the  State  of  Illinois  at  twenty 
millions  of  dollars,  which  means  that  the  damage 
averages  5G  cents  to  each  acre.*  Fifty-six  cents  per 
acre  for  the  damage  done  by  insects  is  hardly  an  over- 
estimate, and  it  is  probable  that  there  are  few  farmers 
whose  crops  are  not  damaged  to  this  extent.  But  let 
us  take  for  our  example  the  State  of  Virginia  and  con- 
sider only  the  cultivated  land.  Forests  we  will  not 
consider,  though  they  are  often  much  damaged  by  insect 
pests.  We  will  assume  that  there  are  9,000,000  acres 
of  land  under  cultivation  in  Virginia,  and  that  the 
crops  from  this  amount  of  land  are  damaged  by  insects 

♦Report  of  Conn.  Board  of  Agr.,  1899.  p.  78. 


INSECTIVOROUS    BIRDS 

to  the  extent  of  only  50  cents  per  acre.  This  would 
ma  that  insects  destroy  each  year  in  Virginia  four 
and  one-half  million  dollars'  worth  of  farm  crops.  If 
the  damage  were  only  10  cents  per  acre,  the  Loss  would 
still  be  nearly  a  million  dollars.  But  50  cents  is  a  low 
estimate,  and  we  may  saf.lv  say  that  each  year  in  the 
Btttc  of  Virginia  four  and  one-half  million  dollars' 
worth  of  farm  produce  is  destroyed  hy  insects.  This  is 
an  fiBOrmoUJ  loss,  and  the  fanners  should  welcome  any 
means  of  checking  it. 

213.  Insects  Eaten  by  Birds. — Now,  have  we  no 
means  at  hand  of  lessening  the  number  of  destructive 
l.irds  that  make  inscctl  their  principal  food 
mwA  d. -troy  great  numbers.  Anyone  who  is  at  all 
obserrafil  must  have  noticed  how  many  birds  are  con- 
stantly pursuing  insects.  The  robin  is  busy  most  of 
the  day,  hopping  about  on  the  ground  picking  up  the 
1 1  that  constitute  its  food ;  we  have  all  seen  these 
birds  at  work,  and  also  the  many  birds  feeding  in  the 
air  and  on  the  trees.  We  must  have  noticed  them.  But 
if  better  proof  than  our  own  observation  ia  d. ->ired,  we 
have  it  from  good  authority.  "Professor  Forbes, 
Director  of  the  Illinois  State  Laboratory  of  Natural 
History,  found  17*>  larvae  of  Bibio — a  11  v.  which,  in  the 
larval  stage,  feeds  on  the  roots  of  grass — in  the 
stomach  of  a  single  robin,  and  the  intestines  contained 
probably  as  many  more."*  Another  excellent  authority 
states:  "In  a  certain  town  where  the  ehns  had  been 
ruined  for  several  years,  the  cedar  birds  appeared  and 
the  elms  were  afterward!  comparatively  free  from  these 
•Report  of  Conn.  Board  of  Agr.,  1800,  p.  77. 


ELEMENTS   OF   AGRICULTURE 

destructive  beetles.  It  has  also  been  shown  that  thirty 
cedar  birds  would  destroy  9,000  worms  during  the 
month  when  the  cutworm  caterpillar  is  exposed/'* 

"We  might  add  many  hundred  examples  like  the  above 
to  show  the  great  number  of  insects  destroyed  by  birds. 
It  is  very  reasonable  to  suppose  that  the  more  birds  we 
have  about,  the  more  insects  will  be  eaten.  Professor 
Forbes  estimates  the  number  of  birds  in  Illinois  at  three 
individuals  to  the  acre,  f  In  Virginia  there  are  probably 
as  many  birds  to  the  acre  as  there  are  in  Illinois,  so  we 
may  assume  that  there  are  three  birds  to  each  acre  of 
land  in  Virginia.  This  would  give  us  for  this  State 
something  like  eighty  million  birds.  Suppose  that  each 
bird  destroys  only  one  insect  a  day,  it  would  mean 
the  destruction  of  eighty  million  insects.  One  insect 
a  day  to  each  bird,  however,  is  too  low  an  estimate; 
twenty  insects  to  each  bird  would  be  more  probable. 
To  be  on  the  safe  side,  then,  let  us  assume  that  two- 
thirds  of  the  total  number  of  birds,  or  53,000,000, 
eat  insects,  and  that  each  individual  bird  eats  an 
average  of  ten  insects  a  day.  This  would  mean  530,- 
000,000  insects  destroyed  each  day  by  birds.  Could 
there  be  a  more  effective  way  of  destroying  them? 
Could  we  but  add  to  the  number  of  insect-eating  birds 
within  the  state  of  Virginia  only  one  individual  to  each 
acre  of  ground,  it  would  mean  the  destruction  of  mil- 
lions of  insects,  and  a  saving  of  many  thousand  dollars 
to  the  farmers  and  fruit  growers.  Yet  no  efforts  are 
made  to  increase  the  number  of  such  birds;  on  the  con- 

•Report  of  Conn.  Board  of  Agr.,  1899,  p.  83. 
flbid,  p.  77. 


I\-KCTIVOROU8   BIKD8  225 

trary,  it  is  probable  that  the  number  of  these  insect- 
row  ing  lesi  each  year. 
214.  The  Birds  that  Eat  Insects. — Now,  what  birds 
may  be  classed  as  insect-eaters?    There  are  birds  that 
li\<'   almost  exclusively   on   insects,   eating   practically 
getable  food;  there  are  others  that  live  on  both 
inaecta  and  vegetable  food;  and  there  is  still  another 
class  that  lives  almost  ex< -lusively  on  vegetable  food, 
eating  only  a  few  insects.     We  can  mention  separately 
only  a  few  of  the  commoner  varieties  of  birds — those 
usually  seen  about  the  aremge  farm: 

Under  the  class  of  insect-eaters  we  may  mention 
swallows,  of  which  there  are  several  varieties;  the  best 
known  being  the  barn-Swallow,  tree-swallow,  eave  or 
cliff-swallow,  and  the  hank-swallow.  These  hinls  build 
about  the  dwellings  of  man,  and  may  be  seen  during  the 
ircling  about  in  search  of  insects.  As  these  birds 
lusively  on  insects,  they  are  of  much 
value,  ami  their  presence  should  be  encouraged  in 
way  possible.  "  It  is  said  that  cliff  and  barn-swallows 
can  be  induced  to  build  their  nests  in  a  particular 
locality,  otherwise  irritable,  by  providing  a  quantity  of 
mud  to  he  used  n-  mortar.  Rarn-swallows  may  also  be 
enoonragad  b\  catting  a  small  hole  in  the  gables  of  the 
harm"*  The  purple  martin  also  belongs  to  this  family 
of  birds,  and  is  very  useful  ai  an  mtfiflt  flofltTOJfil  The 
so-called  chimney-swallow  is  not  a  swallow  at  all,  but 
should  be  called  a  swift.  It,  too,  feeds  largely  on  insects. 
In  the  afternoons  of  summer   and    fall,  we   often  see. 

•U.S.  Dept.  Agr.  Farmer*'  Bulletin  No.  Si. 
15 


226  ELEMENTS   OF   AGRICULTURE 

numbers  of  nighthawks,  commonly  known  as  bullbats, 
darting  about  through  the  air  in  search  of  food.  These 
birds  live  exclusively  on  insects,  and  should  be  pro- 
tected, instead  of  being  shot.  The  whippoorwfll  is  a 
bird  that  works  entirely  by  night,  and  it,  too,  lives  on 
insects.  Of  all  the  insect-eating  birds  that  inhabit 
farms,  there  is  none  of  more  value  than  the  common 
house  wren.  Fully  98  per  cent  of  its  food  is  made  up 
of  insects,  most  of  which  work  destruction  to  farm 
crops.  The  kingbird  is  another  insect-eater,  and  is  also 
of  value  to  the  farmyard  as  a  watchman,  driving  off 
birds  of  prey.  The  cuckoo  also  lives  largely  on  insects, 
and  is  especially  fond  of  caterpillars.  The  phcebe,  a 
quiet  little  bird,  lives  almost  exclusively  on  insects,  and 
is  a  very  valuable  bird  on  the  farm.  There  are  five  or 
six  different  kinds  of  woodpeckers  in  the  eastern 
United  States,  and  they  destroy  many  insects  that  prey 
on  fruit  and  forest  trees.  They  also  eat  some  vegetable 
food,  but  do  little  or  no  damage  to  crops.  The  meadow 
lark,  or  old-field  lark,  is  another  bird  that  makes  its 
living  largely  on  insects.  Its  vegetable  food  consists  of 
the  seed  of  weeds.  So  it  is  of  benefit  to  the  farm  in 
two  ways.  The  brown  thrasher  is  another  insect-de- 
stroyer, more  than  half  of- its  food  being  made  up  of 
insects.  The  bluebird  eats  mostly  insects,  which  make 
up  fully  three-fourths  of  its  food.  The  Baltimore  oriole, 
famous  for  its  beauty  and  song,  is  another  insect-de- 
stroyer, and  should  be  made  welcome  everywhere.  The 
robin  is  a  bird  well  known  to  everyone,  but  its  value 
to  the  farm  is  far  from  being  known.  The  robin,  while 
it  eats    some   vegetable    food,  destroys  many  harmful 


□res  rzvoBOua  mnos  227 

insects;  about  one-half  of  its  food  being  made  up  of 
insects.  The  catbird,  against  which  there  is  such  an 
unreasonable  prejudice,  is  another  insect-destroyer; 
shout  one-half  o!  ttfl  food  consists  of  insects,  li  il 
claimed  that  the  bird  destroys  -nine  fruit;  but 
if  it  does,  it  payi  for  all  it  takes  bj  destroying  hnndreda 

of  harmful  insects;  and  in  tlii>  wav  duv>  more  good  than 

harm  to  the  fruit  grower. 
There  ere  many  other  birds  thai  destroy  insect-,  bul 

we  have  Dot  ipace  to  mention  them  all  individually,  ami 
tell  of  their  good  work:  to  We  mu>t  pass  on  to  consider 

the  seed-eating  birds. 

Questions 

1.  How  do  insects  damage  growing  crops?  2.  At  what 
stage  of  growth  are  most  crops  subject  to  the  attacks  of 
insects?  3.  About  what  is  the  estimated  damage  per  acre 
by  insects  in  the  State  of  Illinois?  4.  About  how  many 
birds  are  there  to  the  acre  in  Illinois?  5.  About  how  many 
insects  do  birds  eat  a  day  in  the  State  of  Virginia?  6.  Name 
a  few  of  the  best  known  insect-eating  birds  in  your  neigh- 
borhood. 7.  Tell  what  you  know  about  the  kind  cf  food 
eaten  by  the  Hfferent  birds  with  which  you  are  familiar. 

PROBLEMS 

1.  Suppose*  the  annual  damage  from  Insects  in  your  State 
averages  30  cents  per  acre,  what  is  the  yearly  damage  for 
the  State? 

2.  Suppose  there  are  four  birds  to  the  acre  in  your  State, 
about  how  many  will  there  be  for  the  whole  State? 

3.  Suppose  each  bird  in  your  State  eats  Ave  insects  a  day. 
how  rxiny  will  all  the  birds  destroy  in  a  week? 


228  ELEMENTS   OF  AGEICULTUEE 


CHAPTER  XLIIL— Seed-Eating  Birds 

215.  The  Destruction  of  Weeds. — The  successful 
farmer  must  spend  a  part  of  his  time  and  some  money 
in  fighting  weeds.  The  amount  of  time  and  money 
he  spends  depends  on  how  clean  .he  keeps  his  farm. 
Weeds  have  been  well  defined  as  plants  in  the  wron 
place.  Naturally  all  thrifty  farmers  are  interested  in 
the  destruction  of  weeds.  They  plow  them  under,  they 
dig  them  up,  and  pull  them  out  by  hand,  .and  yet  some 
escape  to  start  a  new  crop  the  next  season.  Most  weeds 
produce  great  crops  of  seed;  some  weeds  are  known 
that  produce  about  one  hundred  thousand  seed  to  a 
single  plant.  If  there  were  not  some  means  of  destroy- 
ing at  least  a  part  of  the  seed  produced  by  weeds,  the 
world  would  soon  be  overrun  with  them.  Fortunately, 
there  are  fully  fifty  different  kinds  of  birds  that  eat  the 
seed  of  weeds,  and  the  amount  of  seed  destroyed  by 
these  birds  is  enormous.  We  can  only  mention  a  few  of 
the  birds  individually. 

216.  Birds  that  Destroy  Weeds. — Probably  the  best 
known  seed-eating  birds  are  sparrows.  Beal  says  of  the 
sparrows  that  "there  are  some  forty  species,  with  nearly 
as  many  subspecies,  in  North  America,  but  their  dif- 
ferences, both  in  plumage  and  habits,  are  in  most  cases 
too  obscure  to  be  readily  recognized,  and  not  more  than 
half  a  dozen  forms  are  generally  known  in  any  one 
locality/'* 

*U.  S.  Dept.  Agr.  Farmers'  Bulletin  No.  54. 


SEEt>-fcATmo  BlfiDS  tit 

To  give  some  idea  of  the  amount  of  seed  eaten  by 
sparrow-.  Bet!  has  made  some  estimates  for  the  State 
of  Iowa.  II-  ives  U  figures  for  only  one  kind  of  spar- 
row, namely,  the  tree-sparrow,  which  is  rery  abundant 
in  t lu*  Northern  Statea.  He  begina  by  estimating  thai 
are  ten  Bparrowi  to  each  square  mile,  or  one  Bpar- 
r<»\\  to  Bixty-four  acres.  If,  as  he  says,  each  spat-row 
eats  daily  an  average  of  one-fourth  of  an  ounce  of  seed 
for  two  hundred  days,  they  destroy  in  thai  State  alone 
,000  pounds,  or  875  tons  oi  weed-seed;  allowing 
20,000  pounds  to  a  car-load,  this  is  enough  seed  to  load 
a  little  over  eighty-seven  car-,      besides  this  one  kind 

of  sparrow  there  are  many  others  that  eat  largely  hi 

and  the  amount  of  seed  destroyed  must  be  much 
larger  than  these  figures  show.  Suppose  instead  of  be- 
ing eaten  by  birds  this  vast  quantity  of  seed  were  to 
grow  up  as  weeds,  what  would  become  of  the  farmers? 
In  the  Southern  States,  while  we  have  not  the  tree- 
sparrow,  we  have  a  number  of  equally  useful  varieties, 
SUCh  as  the   white-throated  epaiTOW,  the   white-t row  ned 

sparrow,  the  song-sparrow,  the  field-sparrow,  the  fox- 

BparrOWj  and  8  number  of  other-.     du-t  stop  a  moment 
and  try  to  think  of  the  vast  number  of  weed  SQCd 

each  winter  by  the  sparrows  in  each  State,    Even  the 
much  aDueed  English  sparrow  is  known  t<»  eal  the  seed 

of  many  WOOds, 

While  sparrows  are  noti 
they    do    not    by    any    mean-     ronline     tbeui-elves    to   8 

table  diet    Daring  the  summer,  and  especially  in 

the  breeding  sea -on,  they  eal  many  insects,  and  probably 
feed  their  \oung  largely  upon  the  same  food.    An  ex- 


930  EtEMEfttS   OF  AGKiCtJLTURE 

amination  of  the  stomachs  of  three  species — the  sdng 
sparrow,  the  chipping  sparrow  and  the  field  sparrow- 
shows  that  about  one-third  of  the  food  consists  of  in^ 
sects,  comprising  many  injurious  beetles,  such  as  snout- 
beetles  or  weevils,  and  leaf-beetles/'* 

Besides  the  sparrow  there  are  a  number  of  other 
kinds  of  birds  noted  as  seed-destroyers.  The  goldfinch, 
or  wild  canary,  is  very  useful  in  this  respect.  Redbirds, 
horned  larks,  .and  blackbirds  are  also  seed-eaters.  The 
blackbirds  with  which  we  of  the  southeastern  States 
are  most  familiar  are  the  crow  blackbird,  or  grackle, 
and  the  red-winged  blackbird.  Both  of  these  birds  are 
accused  of  stealing  grain  from  cultivated  fields,  and  it 
is  very  probable  that,  they  do  some  damage  in  this  way ; 
but,  on  the  other  hand,  they  eat  quantities  of  weed-seed 
and  also  many  insects. 

Besides  the  birds  already  mentioned,  there  are  several 
so-called  game  birds  that  are  seed-eaters.  The  quail, 
or  bobwhite,  lives  largely  on  the  seed  of  weeds,  and  does 
no  harm  to  grain  fields.  The  mourning  dove  is  another 
bird  that  eats  great  quantities  of  weed-seed. 

Dr.  Sylvester  Judd,  of  the  United  States  Department 
of  Agriculture,  says  of  seed-eating  birds:  "  Xo  less  than 
fifty  different  birds  *act  as  weed-destroyers,  and  the 
noxious  plants  which  they  help  to  eradicate  number 
more  than  threescore  species/'  f 

217.  Birds  and  Cultivated  Crops. — On  the  other  hand, 
it  is  undoubtedly  true  that  some  birds  do  damage  to 
both  grain  crops  and  fruit  crops.     The  crow  and  the 

*U.  S.  Dept.  Agr.  Farmers'  Bulletin  No.  54. 
+Yearbook  U.  S.  Dept.  Agr,  1898,  p.  282. 


8EKI»  1  ATIN(.    IUKD8  231 

two  kinds  «>f  blackbirds  already  mentioned  ire  the  chief 
offenders,  and  in  some  sections  of  the  country  they  are 
considered  pests,  Where  the  blackbirds  gsther  in  reiy 
•i<»ik-  they  do  considerable  damage  to  grain.  But 
it  is  vary  probable  t hat  the  destruction  of  grain  is  doe 
to  the  lack  of  other  food,  tor  even  when  they  can  get 
cultivated  grain  tl  Bd  and  in 

and  while  they  do  some  damage  they  certainly  do  some 
good. 

The  crow  is  accused  of  pulling  up  young  corn,  and  is 

probably  guilty  of  this  crime ;  but,  on  the  other  hand, 

ahmit  Z&  per  rent  of  the  CTOl  ft  food  consists  of  harmful 

ta,  and  the  numher  of  such   insects  destroyed  by 

crows  must  be  immen- 

Robins,  catbirds,  and  mocking-birds  are  often  accused 
of  taking  fruit,  but   the  best  testimony  show 

that  the  value  of  the  fruit  eaten  hv  them  is  hut  small, 
and  i>  paid  for  many  times  over  hv  the  number  <>f  harm- 
ful inserts  destroyed. 

Questions 

1  What  aid  the  farmer  in  his  fight  against  weeds? 
2.  About  how  many  kinds  of  birds  are  known  to  eat  the 
seed  of  weeds?  3.  Name  some  of  the  best  known  seed- 
eating  bn-ds.  4.  Give  some  idea  of  the  amount  of  seed 
eaten  by  the  tree  sparrow  in  Iowa.  5.  What  can  you  say 
in  defense  of  the  blackbird  and  the  crow? 

PROBLEM 

Suppose  that  in  your  State  there  are  ten  sparrows  to  each 
square  mile,  and  that  each  sparrow  eats  one-fourth  of  an 
ounce  of  seed  a  day  for  one  hundred  and  fifty  days.  How 
many  pounds  of  seed  will  be  eaten  during  that  time  in  the 
State?  How  many  car-loads  will  that  amount  of  seed 
make,  allowing  20.000  pounds  to  the  car? 


232 


ELEMENTS    OF   AGRICULTURE 


CHAPTEE  XLIV.— Birds  of  Prey 

218.  Prejudice  Against  Hawks  and  Owls. — We  come 
now  to  a  class  of  birds  a  part  of  whose  food  consists  of 
small  animals  and  birds.  They  are  known  as  birds  of 
prey.  The  birds  of  prey  in  which  we  are  interested  are 
generally  known  as  hawks  and  owls,  and  of  both  there 
are  a  number  of  different  kinds.  Against  all  birds  of 
prey  alike,  there  exists  the  strongest  prejudice;  they 
are  without  exception  condemned,  and,  whenever  the 
opportunity  offers,  executed  without  trial.  This  con- 
demnation of  all  birds  of  prey  without  trial  is  hardly 
just.  We  accord  to  our  basest  criminals  a  patient  hear- 
ing. Why,  then,  should  we  not  listen  to  a  few  words 
in  defence  of  birds  of  prey?  But  few  people  will  ever 
listen  to  a  word  spoken  in  defence  of  hawks  or  owls: 
they  condemn  the  whole  class.  The  innocent  must 
suffer  for  the  sins  of  the  guilty,  for  but  few  persons  are 
willing  to  believe  in  an  innocent  hawk  or  owl.  Yet 
there  are  hawks  and  owls  not  only  innocent  of  all  wrong 
against  man,  but  actually  of  great  benefit  to  agriculture. 
It  is  certainly  unjust  to  condemn  these  birds  to  death 
because  a  few  of  their  cousins  have  been  known  to  steal 
poultry.  It  would  be  just  as  reasonable  to  condemn  a 
whole  family  to  death  because  one  member  was  a  thief; 
or  to  judge  the  character  of  the  human  race  by  a  few 
criminals.  But,  you  may  object,  how  can  this  preju- 
dice against  hawks  and  owls  have  become  so  universal 
without  good  foundation  ?    That  there  is  some  founda- 


HllJh-     OF     IMM  V  233 

tion  for  the  feeling  la  rerj  true.  There  are  hawks  and 
owh  ihai  attack  poultry  or  small  game  whenever  the 
opportunity  offers,  l>ut  this  i>  l>v  no  means  true  of  the 
whole  race.    There  are  many  kinds  of  hawks  and  owls 

tluil  are  never  known  to  touch  poultry,  rnfortunately, 
few  persons  can  distinguish  the  different  kinds  of  hawks 
Of  "wis.  They  see  some  bird  of  prej  attack  their  fowls 
and  at  once  condemn,  and,  whenever  possible,  kill  all 
birds  that  resemble  it.  In  doing  this  they  kill  manv 
innocent  birds,  and  very  probably  never  reach  the  guilty 
one:  for  the  birds  that  rob  the  henroosts  are  very  quick 
and  shy,  and  fully  realise  the  danger  from  a  urnn.  On 
the  other  hand,  their  cousins  who  never  touch  a  domes* 
OWl,  and    come,  conscious  of    their    innoocn 

search  of  mice  or  insects,  arc  greeted  with  shot  tnto  tided 

for  the  thief. 

Unfortunately,  it  would  require  far  too  much  space 
for  us  to  attempt  to  describe  each  kind  of  hawk  and 
owl.  We  can.  howerer,  tell  of  some  of  their  good  deeds 
as  compared  with  the  harm  that  they  do,  and  urge  on 
all  to  give  to  these  valuable  bird-  at  least  a  fair  trial. 
The  harm  that  these  birds  do  i>  easily  told:  the 
that  they  do  would  till  a  volume.     Let   DS  SOS  what  thev 

have  done  to  bring  upon  themselves  the  curse  of  man. 

219.  Harm  Done  by  Hawks  and  Owls. —  The  git 
crime  of  which  these  bar  rased  is  the  dc-t  ruction 

of  poultry  and  I.     Now,  there  are  only   two 

kinds  of  hawks  commonly  found  in  the  Tinted  States 
that  feed  principally  on  the  tlesh  of  other  birds.     I 
are  known  as  Cooper's  hawk,  and  the  sharp-shinned 
hawk,  and  are  much  alike  in  appearance,  Coopers  haw  k 


234  ELEMENTS   OF  AGRICULTURE 

being  the  larger.  These  birds  are  very  quiet  and  shy, 
darting  suddenly  on  their  prey  from  some  hiding-place. 
Earely  are  they  seen  soaring  over  fields  or  heard  calling. 
There  are  two  other  bird-eating  hawks  sometimes  seen 
in  the  country,  the  goshawk  and  the  duck-hawk,  but, 
fortunately,  they  are  few  in  numbers.  These  four  kinds 
of  hawk  are  harmful,  as  they  destroy  many  useful  birds, 
and  do  little,  if  any,  good.  All  the  other  hawks  and 
owls  known  in  the  United  States  do  good  as  well  as 
harm.  Some  kinds  are  entirely  beneficial,  others  prin- 
cipally beneficial,  and  still  others  in  which  the  beneficial 
and  harmful  qualities  are  about  equally  balanced.  To 
recognize  these  many  kinds  of  birds  requires  more  time 
and  study  than  the  average  farmer  can  devote  to  it. 
How  then  can  he  punish  the  guilty  without  the  innocent 
suffering  ?  Chapman  says :  "  The  only  safe  way  to  give 
justice  to  whom  justice  is  due  is  to  kill  only  the  hawks 
we  actually  see  taking  our  chickens,  and  not  murder 
indiscriminately  every  member  of  the  hawk  family.'7* 

There  are  only  a  few  owls  known  in  this  country  that 
ever  disturb  poultry,  and  they  also  do  much  good  in 
destroying  many  mice  and  rats.  The  owls  work  only 
at  night,  and  when  poultry  are  provided  with  a  home 
they  are  perfectly  safe  from  this  bird. 

220.  Value  to  the  Fanner  of  Birds  of  Prey. — In  the 
report  for  1886,  Dr.  C.  H.  Merriam,  chief  of  the 
Biographical  Survey  of  the  Department  of  Agriculture, 
gives  some  interesting  figures  showing  the  value  of  birds 
of  prey  in  Pennsylvania.    "  On  the  23d  of  June,  1885/' 

•Report  of  Conn.  Board  of  Agr.,  1899,  p.  103. 


MfcDs  of  put?  235 

he  tells  Us,  "  the  legislature  of  Pennsylvania  passed  an 
id  known  as  tin-  'scalp  act,*  ostensibly  'for  the  benefit 
of  agriculture,'  which  provides  i  bounty  «•!'  50  cents' 
cm  h  on  hawks,  owls,  weasela,  snd  minks  killed  within 
the  limits  of  the  State  ami  a  fee  of  20  cents  to  the 
notary  or  justice  taking  the  Affidavit 

■  !'.\  virtus  of  tbie  ad  ahum  $9Q,000  has  been  paid 
in  bounties  during  the  year  end  ■  ball  thai  has  elapsed 
since  the  law  wmt  into  effect  This  represent!  the 
destruction  of  at  least  128,571  of  the  above-mentioned 
animals,  most  of  which  were  hawks  and  owls. 

"Granting   thai    5,000  chickens  are   killed   annually 

nnsvlvania  bjf  hawks  ami  owls,  ami  that   they  are 

worth  U  centfl  each  (a  liheral  estimate  in  view  of  the 

fact  that  a  fogs,  portion  of  them  are  killed  when  very 

young),  the  total  loss  would  be  $1,250,  and  the  poultry 

killed  in  a  year  and  a  half  would  he  worth  $1,875.  ETence 
it   appear-  that    during   the   past    eighteen    months    the 

of  Pennsyrvanis  ha-  expended  I  re  the 

farmer  a  loaf  of  $1^875.  I » 1 1 1  this  estimate  h\  no  means 
represents  the  actual  loss  to  the  farmer  and  taxpayer 
of  the  State.  It  i-  within  hounds  to  say  that  in  the 
course  of  a  yeai  every  hawk  and  owl  destroys  at  lead 

a  thousand  n  teir  equivalent   in  insects,  and 

that  each  mouse  ur  'l<  snuivnlenl  -  <d  would 

i  a  dm  the  farmers  a  loss  i  snbj  per  annum.  There- 

omitting  all  reft  ren<  •■  to  the  numerous  increase  in 
the  numberi  of  these  noxious  animals  when  nature's 
as  of  holding  them  in  check  has  bean  removed,  tho 
lowest  possible  estimate  of  tho  value  to  the  tarn 


236  ELEMENTS  Off  AGRiCtJLTtfRE 

each  hawk,  owl,  and  weasel  would  be  $20  a  year,  or,  $30 
in  a  year  and  a  half. 

"  Hence,  in  addition  to  the  .$90,000  actually  expended 
by  the  State  in  destroying  128^571  of  its  benefactors^ 
it  has  incurred  a  loss  to  its  agricultural  interests  of  at 
least  $3,857,130,  or  a  total  loss  of  $3,947,130  in  a  year 
and  a  half,  which  is  at  the  rate  of  $2,631,420  per  annum. 
In  other  words,  the  State  has  thrown  away  $2,105  for 
every  dollar  saved!  And  even  this  does  not  represent 
fairly  the  full  loss,  for  the  slaughter  of  such  a  vast 
number  of  predaceous  birds  and  mammals  is  almost 
certain  to  be  followed  by  a  correspondingly  enormous 
increase  in  the  numbers  of  mice  and  insects  formerly 
held  in  check  by  them,  and  it  will  take  many  years  to 
restore  the  balance  thus  blindly  destroyed  through 
ignorance  of  the  economic  relations  of  oar  common 
birds  and  mammals."* 

A  statement  such  as  this  from  so  reliable  an  authority 
as  Dr.  Merriam  should  go  far  towards  convincing  us 
of  the  folly  of  destroying  all  kinds  of  hawks  and  owls. 

Questions 

1.  What  is  meant  by  birds  of  prey?  2.  Name  the  two 
commonest  kinds  of  birds  of  prey.  3.  Can  you  explain  why 
such  a  strong  prejudice  exists  against  all  hawks  and  owls 
alike?     4.  How  do  most  hawks  and  owls  benefit  farmers? 

5.  About  how  many  kinds  of  hawks  are  there  in  the  United 
States  that  live  exclusively  on  the  flesh  of  other  birds? 

6.  Name  the  two  commonly  found  in  this  country  that  live 
on  the  flesh  of  other  birds.  7.  Give  an  account  of  the  work- 
ing of  the  "Scalp  Act"  in  Pennsylvania. 

•Report  of  Conn.  Board  of  Agr.,  1899,  p.  94. 


B1KDS    OF    PREY  237 


PROBLEM 


Take  the  total  number  of  acres  of  cultivated  land  in  your 
State,  and  suppose  there  are  two  field  mice  to  each  acre, 
and  that  each  mouse  eats  two  cents  worth  of  food  per  year. 
What  is  the  value  of  the  food  eaten  by  the  mice?  If  the 
hawks  and  owls  eat  one  mouse  for  each  two  acres  of  land, 
what  is  the  value  of  food  saved? 


238 


ELEMENTS   OF   AGEICULTUBE 


CHAPTER  XLV.—Forestey 

221.  Definition. — Forestry  is  the  art  of  growing  and 
caring  for  trees;  it  is  tree-farming.  In  this  great  coun- 
try of  ours  we  are  inclined  to  look  on  tree-farming  as 
a  useless  occupation.  With-  such  vast  forests  as  ours 
it  seems  useless  to  plant  and  grow  more  trees.  But  at 
the  present  rate,  how  long  will  our  forests  last  ?  Each 
year  many  thousand  trees  are  cut,  and  it  takes  many 
years  for  others  to  grow  in  their  place.  A  great  tree 
may  he  cut  down  in  a  few  minutes;  hut  it  requires  fifty 
to  one  hundred  years  for  another  to  grow  in  its  place. 
Our  forests  are  being  cut  away  much  faster  than  others 
are  growing,  and  unless  our  government  takes  some 
measure  to  protect  them,  the  forests  of  this  country 
will  all  he  destroyed. 

222.  Value  of  Forests. — Besides  supplying  timber, 
forests  are  of  value  in  many  ways : 

(1)  In  the  first  place  forests  have  a  great  influence 
on  the  climate  of  a  country.  The  trees  through  their 
leaves  give  off  vast  quantities  of  water,  which  serves  to 
keep  the  air  in  the  immediate  vicinity  of  the  forest 
moist.  The  moisture  in  the  air  serves  to  equalize  the 
temperature,  preventing  sudden  extremes  of  heat  and 
cold. 

(2)  Forests  prevent  excessive  surface  washing, 
causing  the  rains  and  snow  to  soak  into  the  soil;  thus 
increasing  the  flow  of  water  from  springs,  wells,  and 
creeks,  and  at  the  same  time  preventing  floods.     The 


FORES  IK  V 


889 


great  floods  that  occur  each  year  in  our  rivers  are,  in 
a  large  measure,  <lue  to  the  cutting  away  of  the  forest 
■haul  the  sources  of  the  rivers.  There  being  no  trees 
to  iton  its  flow,  the  water  rashes  awav  in  gullies  to 
increase  the  volume  of  creeks  and  rivers.  The  dreadful 
floods  that  lake  place  each  year  in  the  great  Mississippi 
River  are  DO  doubt  made  worse  by  the  cutting  away  of 
the  f<»rrsts  which  surround  its  headwaters.  Tli. 
every  reason  to  believe  that  the  floods  in  this  river  will 
grow  worse  as  more  of  the  forest  in  the  valleys  is  cut 
away. 

prevent  in  a  great  measure  the  surface 
evaporation  which  takes  away  such  vast  quantit 
water  from  treeless  soil.  Through  surface  evaporation 
and  surface  washing,  soils  from  which  trees  have  been 
cut.  unless  continually  cultivated,  are  apt  to  sutTer.  The 
cutting  of  timber  is  often  followed  by  forest   fire-  that 

destroy  the  undergrowth,  leaving  the  soil  bare  to  the 

aeti<»n  of    wind    and    rain.      In  this  condition  it 
moisture.  rtility,  and    quickly    becomes    waste 

land.  The  cutting  away  of  forests  always  lessens  the 
water  supply. 

(t)    !  a   great    protection    against    wind- 

storm-: the]  protect  cultivated  crops  from  both  the 
cold  windl  of  winter  and  the  hot,  drying  winds  of 
summer. 

223.  Destruction  of  Forests. — Vast  numbers  of  trees 

for  timber,  and  often  the  suiting  is 

bo  Chi  done  thai    many  young  trees  are  injured 

or  destroyed.    The  modern  procesi  of  manufacturing 

paper   from    wood    pulp   is   also   responsible   for   the 


240  ELEMENTS   OP   AGRICULTURE 

destruction  of  much  timber.  Soft  timber  is  principally 
used  in  this  process,  and  the  amount  of  timber  cut 
annually  is  immense.  But  the  great  forest  destroyer 
is  fire;  each  year  vast  areas  of  wooded  land  are  burned 
over,  and  most  of  the  young  timber  destroyed.  After 
a  forest  has  been  cut,  the  young  timber,  if  left  undis- 
turbed, will  in  twenty-five  to  forty  years  produce  a  new 
forest,  but  after  a  fire  there  are  few  young  trees  left 
to  grow.  Each  State  has  laws  against  starting  forest 
fires,  imposing  as  penalties  heavy  fines  or  imprisonment. 
Unfortunately,  the  law  is  never  enforced,  and  fires  that 
destroy  thousands  of  dollars'  worth  of  timber  are  some- 
times started  merely  for  the  sake  of  obtaining  a  few 
chestnuts.  Besides  destroying  the  young  growth,  forest 
fires,  which  usually  occur  in  the  fall,  leave  the  land 
comparatively  bare  to  the  action  of  winter  rains,  which 
do  much  injury  to  the  exposed  soil. 

Lumber  companies  buy  up  great  areas  of  forest  land 
merely  for  the  lumber;  they  cut  off  the  trees,  caring 
nothing  for  another  crop,  and  after  obtaining  the  lum- 
ber often  leave  the  land  to  the  action  of  fire  and  water. 
Under  the  present  system  of  management  the  forests 
of  the  United  States  will  certainly  be  destroyed  in  a 
comparatively  few  years,  and  the  next  generation  will 
have  to  begin  to  grow  trees  as  a  regular  crop.  Conserva- 
tive estimates  show  that  at  the  present  rate  of  destruc- 
tion the  forests  of  the  United  States  will  not  last  more 
than  fifty  years. 

224.  Tree-Growing  for  Profit. — Forestry  among 
other  things  teaches  us  how  to  grow  crops  of  trees  for 
market.    By  exercising  the  proper  amount  of  care  and 


1      !    !      [RT  241 

following  a  few  siinple  rules,  any  one  who  owns  timber 
Kind  may  harvest  a  (Top  of  Umbel  ju-t  ai  regurarly  as 
he  barresti  wheal  or  corn.    I<<t  m  suppose  the  a 
i  farmer  who  omu  WO  aerea  of  woodland  and  wishes 

t.»  derive  ;m  income  from  the  sale  «»f  timber.    Now.  he 

cm  in  :i  short  time  cut  all  of  his  trec<  that  are  tit   for 
lumber,  hut   if  lie  wishes  another  crop  from  tin-  -nine 

land  he  must  wail  many  yen-.  It",  however,  he  i 
to  derive  i  steady  income  from  his  timber  he  can  cut 
only  a  part  of  it  each  year.  He  can  divide  his  200 
into  sections  of  say  ten  acres  each,  and  cut  the 
timber  from  one  section  each  year;  being  careful  to 
protect  the  yonng  timber  from  harm.  By  the  time  he 
has  cut  over  his  200  acres  the  young  timber  on  the  first 
ten  acres  tut  has  had  twenty  years  added  to  its  growth, 
and  much  of  it  will  be  ready  for  cutting.  In  this  way 
he  derives  a  steady  annual  income  from  his  timber. 
Instead  of  cutting  each  year,  he  may  cut  a  certain  area 
two,  three,  or  four  year.-;  Bay  twenty  acres  even- 
other  year,  or  twenty-five  or  thirty  acres  every  three 
yeart.  By  following  some  system  such  as  this  h- 
derire  a  steady  income  from  his  timber  land,  and  yet 
hand  it  down  to  future  generations  uninjured. 

225.  Growing  Trees  for  Shade  or  Ornament. — Aside 
frotu  their  value  in  forests,  trees  ire  of  value  for  orna- 
mental pnrpoaes  ind  for  the  production  of  -hade.  How 
delightful  after  a  hot  walk  to  enter  the  cool  shade  of 
a  group  of  tret  il     M  uri   toiling  along  a  hot, 

dnsty  road  hails  with  joy  the  ippearance  of  a  tn 

how  few  of  our  public  highways  are  provided  with  shade 
trees.    In  building  a  road  the  deal  ruction  of  all  shade 


242  ELEMENTS   OF   AGRICULTURE 

trees  is  often  the  first  object.  Miles  and  miles  of  road 
stretch  away  without  so  much  as  a  bush  to  shield  the 
traveler  from  the  fierce  summer  sun.  The  idea  prevails 
that  trees  keep  a  roadbed  damp,  but  this  is  true  only 
where  the  soil  is  naturally  very  damp.  A  properly 
constructed  road  is  never  injured  by  shade  trees,  but  on 
the  other  hand  is  made  very  much  more  comfortable 
for  travelers. 

Xo  pasture  should  be  without  its  group  of  shade 
trees;  if  unprovided  with  shade,  animals  suffer  very 
much  from  the  summer  sun.  In  the  heat  of  the  day 
they  love  to  collect  in  the  shade  of  some  tree  and  wait 
for  the  cooler  hours  of  the  day,  during  which  they  feed. 
No  pasture  is  complete  without  its  shade  trees  for  the 
protection  of  animals  during  the  heat  of  the  day. 

For  ornamenting  and  shading  the  grounds  about 
dwellings,  trees  are  often  grown,  and  for  this  purpose 
various  kinds  of  trees  and  shrubs  are  used  according 
to  the  fancy  of  the  owner.  Xo  country  home  is  com- 
plete without  its  setting  of  ornamental  trees  or  shrubs, 
and  the  market  value  of  a  place  may  be  increased  by  a 
growth  of  trees  or  shrubs  about  the  house. 

Questions 

1.  What  is  forestry?  2.  Have  forests  any  effect  on  the 
climate  of  a  country?  3.  If  so,  how?  4.  How  do  forests 
protect  the  surface  oi  the  land?  5.  How  do  forests  check 
the  formation  of  floods?  6.  How  do  forests  protect  the  soil 
from  surface  evaporation?  7.  How  are  forests  destroyed? 
8.  Is  there  any  law  in  your  State  against  starting  forest 
fires?  9.  Does  the  cutting  away  of  the  older  trees  neces- 
sarily destroy  a  forest?  10.  How  may  a  piece  of  wood- 
land be  made  to  yield  an  annual  crop  of  timber?  11.  Of 
what  value  are  trees  in  a  pasture?  12.  Of  what  value  are 
trees  planted  about  a  home? 


KOADS.  243 


CHAPTER  XLVI.— BOAM 

226.  Growth  of  Interest  in  Good  Roads. — There  is  an 
old  Baying  to  the  effect  thai  one  may  jndge#oi  the  civili- 
zation of  i  country  by  iti  roads — the  better  the  roads, 
the  higher  the  civilization.  Savages  have  n<>  roads;  the 
old  Romans  bnill  roads  thai  ate  in  use  to-day.  Frame, 
Germany,  England,  and  the  older  countries  of  Europe 
have  Car  better  roads  than  we  have  in  the  United  states. 

It  i-  in  only  a  few  of  the  more  progressive  State-  of  our 
country  that  sny  road-  worthy  of  being  called  good  are 
to  be  found.     Hut   the  interest   in  »ood  roads 
ing,  and  their  value  to  the  country  through  which  they 

run  i<  gradually  being  recognized.    It  is  a  hard  matter 

to  com  in  t-payer  that  a  few  dollar-  expended 

on  road  improvement  srill  prove  a  paying  investment: 
but  the  lesson  is  being  learned,  and  will  in  time  i 

in   g  iod   road.-. 

227.  What  is  Meant  by  a  Good  Road. — Now.  what  i- 
meant  l>\  a  good  road:  \\\  the  term  good  POad,  as 
ordinarily  used,  is  meant  a  permanent  road,  the  .-urface 
of  which  remains  hard  ami  smooth  regardless  of  the 
weather,  and  which  may  he  ea-dy  traveled  at  all  seasons. 

I  built  to  he  w<r{\  by  many  generations.  Most 
of  our  so-called  roads  are  not   realh  all;  they 

are  trail-,  end  are  moved  about  to  suit  existing  condi- 
tion-     Th.     building  of  roads    such  as  are  generally 
known  in  this  country  is  a  simple  process,  one  that  has 
handed  down  for  thousands  of  years.    The  first 


244  ELEMENTS   OF   AGRICULTURE 

step  is  to  remove  trees  and  other  impassible  obstruc- 
tions; in  enterprising  communities  the  stumps  are 
sometimes  dug  up,  but  the  usual  method  is  to  leave 
them  to  be  worn  away  by  time  and  the  wheels  of  passing 
vehicles.  If  the  land  be  of  sufficient  value,  the  trail  is 
fenced  on  either  side  to  prevent  its  becoming  too  wide. 
Over  this  clearing,  which  is  expected  to  grow  with  no 
assistance  into  a  fully  developed  road,  one  vehicle  fol- 
lows in  the  track  of  another  until  a  well-marked  way  is 
established;  and  usually  deep  ruts  are  cut  into  the  earth, 
and  in  damp  places  great  pools  of  mud  are  churned  up. 
When  the  ruts  and  mudholes  become  too  deep  to  be 
conveniently  filled  with  loose  stones,  or  old  fence  rails, 
a  new  trail  is  opened  around  them.  In  this  manner 
the  course  of  the  road  is  constantly  changing.  It  is 
seldom  that  any  grading  is  attempted.  The  trail  wan- 
ders across  the  country  from  house  to  house,  dodging 
the  worst  obstacles,  and  finally,  after  many  windings, 
reaching  its  destination. 

The  building  of  permanent  highways  is  the  business 
of  the  engineer,  but  every  farmer  should  know  some- 
thing of  road-making  and  road-mending. 

228.  Dirt  Roads. — A  dirt  road  is  one  that  uses  the 
natural  surface  of  the  ground  with  no  attempt  at  im- 
provement except,  such  as  is  obtained  by  drainage  and 
grading. 

(1)  In  locating  roads  of  any  kind  the  first  object 
should  be  to  avoid  steep  grades.  On  dirt  roads  the  grade 
should  never  be  more  than  7  per  cent,  which  means  a 
rise  of  7  feet  in  every  100,  or  369  feet  per  mile.  As 
the  steepness  of  the  grade  increases,  the  load  hauled 


ROADS  145 

must  decrease.    According  to  Gillespie,  if  a  horse  can 
pull  on  a  level  1,000  pounds;  <>n  i  rise  of  1  foot  in  100, 

or  1  per  cent,  be  can  pull  !><hi  pounds;  on  a  rise  <>f  1  foot 

.  or  8  per  sent,  he  can  pull  810  pounds;  on  a  rise 

of  l  foot  in  *.'*»,  of  1  per  cent,  be  can  pull  540  pounds; 
end  on  i  rise  of  i  foot  in  10,  or  10  per  cent,  he  can  pull 

only  250  pounds.     These  figures  -liow  DOW  important  it 

ifl  t«>  avoid  very  steep  grades. 

(2)  Good  drainage  is  equally  u  important  u  good 
grades,  Wet  spots  in  the  road,  if  neglected,  soon  become 
mudholea  which  prevent  the  hauling  of  anything  but 

li^'lit   loads.      All   wei    portions  of  the  road   should   be 

underdrained,  just  as  wet  fields  are  drained,  the  drains 


Fio.  21.— Section  of  macadam  road  with  dirt  tracks  on  either  side. 
Iltebtl  for  surface  drainage.     (After  a  drawing  In  Yearbook, 
U.  8.  Dcpt.  Agr.,  1804.  page  602.) 

constructed  in  the  same  way.    To  carry  off  the 

surface  drainage,  open  ditches  on  either  side  of  the  road 

should  be  constructed.  The  drainage  ditches  must,  of 
course,  hate  some  outlet  into  some  creek  or  gully.  A 
few  dollars  carefully  expended  in  draining  i  road  may 
i  hangs  an  almost  impassable  road  into  i  fairly  good  one. 

Unless  properly  drained  DO  road  can  be  kept  in  good 
condition. 

(3)  The  surface  of  the  ro;id  should  be  wide  enough 
to  accommodate  all   travel,  and   the  center  should  be 

higher  than  the  rides.    Rg  si  how  the  surface 

of  a  well  constructed  road  i-  built  up.    The 

the  road  ihould  be  just  high  enough  above  the  ditches 


246 


ELEMENTS    OP   AGRICULTURE 


to  cause  all  the  surface  water  to  run  off.    If  too  high,  it 
is  apt  to  wash. 

229.  Stone  Roads. — However  well  graded  and  drained 
dirt  roads  may  he,  they  are  certain  to  become  muddy  in 
wet  weather;  and  from  the  passing  of  many  vehicles, 
are  much  cut  up  into  holes  and  ruts.  To  avoid  this,  the 
surface  of  the  road  or  track  may  be  covered  with  some 
hard  material,  such  as  broken  rock,  gravel,  or  oyster 
shells,  which  does  not  become  soft  in  wei  weather. 
Broken  rock  is  the  material  most  generally  employed, 
and  when  properly  used  makes  the  most  dura-ble  of  all 
roads.     There  are  two  kinds  of  stone  roads  in  general 


Fig.  25.— Section  of  macadam 
road. 


Fig.  26. 
road. 


use.  One  was  designed  by  a  Scotchman  named 
Macadam,  and  is  called  a  macadam  road,  the  other  was 
designed  by  another  Scotchman  named  Telford,  and  is 
called  a  telford  road. 

230.  Macadam  Roads. — The  macadam  road  is  built 
by  using  first  a  layer  of  broken  rocks,  none  of  the  pieces 
to  exceed  three  inches  in  diameter;  the  layer  is  rolled 
arid  packed.  On  this  is  placed  another  layer  of  smaller 
pieces  of  crushed  rock,  which  is  likewise  rolled  and 
packed.  Lastly,  a  layer  of  finely  crushed  rock  is  put  on, 
and,  after  being  wet,  is  heavily  rolled. 

231.  Telford  Roads. — The  telford  road  is  somewhat 
similar  to  the  macadam,  except  that  in  place  of  the  first 


B0AD8  247 

layer  of  coarse  broken  rock,  I  layer  of  fin |  I  laid 

in  |  regular  course.  On  this  the  road  is  built  uj)  like 
the  macadam,  i  shows  a  Motion  of  a  macadam 

.  iin.l  Fig.  86  I  Motion  of  telford. 

A  well  constructed  macadam  or  telford  road  will  last 
for  many  years]  and  eoati  little  <>r  nothing  to  keep  in 
good  repair,  Btone  roads  should  have  dirt  tracks  on  one 
or  both  sides.  A  dirt  track  is  pleasant  to  use  in  dry 
weather,  and  saves  wear  on  the  stone  track.  Fig.  24 
shows  such  i  road. 

232.  Value  of  Good  Roads  to  a  Community. — Good 
roads  provide  better  ichools  and  better  education,  bet- 
burchef  and  better  moral-,  better  health  and 
greater  happiness,  more  money  and  better  business. 

(l)  The  value  of  country  Mhooli  depend-  largely  on 

the  condition    01   the   roads.      When    the    road-    bt 
very  bad.  many  children  arc  prevented  from  attending 

►1  regularly,  and  both    the   school   and   children 

suffer.      It    is   not    unusual    for  country  schools  to   be 
I  for  weeks  at  a  time  <  n  account  of  the  condition 

of  the  road*,    Ifany  country  people  who  wish  to  provide 

their  children  a  Lr<»"d  education  are  forced  to  move  into 

sorne  town  to  secure  it    It  is  useless; 
countn  schools  without  good  country  roads. 

Churches  in  the  country  are  as  much  dependent 
on  good  r  Ottntry  schools  are.    When  the  roads 

are  rery  bad,  many  people  stay  away  from  church,  the 
church  suffers,  and  the  people  gradually  become  indif- 
ferent about  attending  at  all.  They  become  lax,  and  the 
morals  of  the  community  suffer     A  country  without 


248  ELEMENTS   OF  AGRICULTURE 

good   roads   can   have  neither   first-class   schools   nor 
first-class  churches. 

(3)  The  happiness  of  most  people  is,  to  a  large 
measure,  dependent  on  the  society  of  their  neighbors. 
Few  people  can  be  happy  when  forced  to  lead  the  life 
of  a  hermit.  In  many  country  districts  the  women  and 
children  are  for  months  cut  off  from  all  society.  They 
become  practically  prisoners,  for  not  only  are  they  cut 
off  from  society,  but  they  are  prevented  from  taking 
any  form  of  outdoor  exercise.  They  are  confined  to  the 
house  or  yard,  and  suffer  both  physically  and  mentally. 

It  is  no  very  unusual  thing  for  persons  in  the  country 
to  be  far  removed  from  all  medical  assistance;  and 
persons  cut  off  from  the  doctor  have  died  from  want  of 
proper  treatment.  Good  roads  bring  more  and  better 
society,  more  health  and  happiness,  and  better  doctors. 

(4)  By  greatly  reducing  the  cost  of  marketing  crops, 
good  roads  increase  the  farmer's  profit.  The  old  saying, 
u  time  is  money,*'  is  particularly  applicable  to  the 
farmer  during  his  busy  seasons.  Over  good  roads  he  can 
in  the  same  time  handle  almost  twice  as  much  produce 
with  less  wear  and  tear  on  his  teams  than  over  roads 
that  are  full  of  rocks  and  mudholes. 

When  we  remember  that  all  the  produce  of  the 
farm,  in  order  to  find  a  market,  must  pass  over  some 
sort  of  road,  we  can  realize  how  important  is  the  ques- 
tion of  good  roads  to  .the  farmer.  In  this  connection, 
some  figures  prepared  by  the  U.  S.  Department  of 
Agriculture  are  of  interest; 


ROADS 


349 


CoM  oj 


= 

■ 
j 
■ 

■ 

«  - 

K 
U 

■oS 

31 
■ 

S9 

-2 

■  = 

OH 
HO 

11  M 
Mj 

5M 

l  \  i 

Eastern  States 

■ILK 

5.9 
6.9 

8  8 
12  6 

8.8 
23.3 

MM 

2,216 

2,409 
2,197 

ion 

32 

27 
31 
26 
22 
22 

$1  89 



Middle-Southern  States 



Pacific  Coast  and  Mountain  States. . 

1.86 

2  72 

3  06 
1  94 
5.12 

Average  for  the  Tinted  States 

12.1 

2,002 

L'-) 

$3.02 

■■  The   total    weight    of   farm   products   in    1895 

estimated  el  219,824*221  tons;  if  the  forest  products 

hauled  over  tin-  public  roads  he  added   to  this,  we  get 

;  tons,  which  at  $3.02  per  ton,  makes  a  total 

for    the    annual    cost    of    battling    on    public    roads  of 

rlv,  if  not   quite,  two-thirds  of  this 

expense  nay  !>.•  saved  by  road  improvement,  and 

thi>  at  a  total  cOSi  of  i  •  ling  the  !  three, 

or  at   inosi     four,  years    hv  bad    road-."     (Circular   1!», 

Offfc  d  [nqnirj .  I     9.  Depi    \r.)* 

Questions 
1.  How  may  the  civilization   of  a  country   be  Judged? 

2.  What  countries  have  the  best  roads  at  the  present  time? 

3.  What  is  meant  by  a  good  road?    4.  Are  there  many  miles 


•Handbook  for  Farmer*  and  Dairymen,  F.  W.  Woll,  p.  160. 


250  ELEMENTS    OF   AGRICULTURE 

of  good  road  in  your  State?  5.  In  locating  a  road  why  is  it 
important  to  consider  the  grade?  6.  Why  is  the  drainage 
of  a  road  important?  7.  What  happens  to  the  surface  of  a 
dirt  road  in  wet  weather?  8.  What  is  a  stone  road? 
9.  Name  two  well  known  kinds  of  stone  roads.  10.  Tell 
how  a  macadam  road  is  constructed.  11.  Tell  how  a  telford 
road  is  constructed.  12.  How  do  good  roads  improve  coun- 
try schools?  13.  What  effect  have  good  roads  on  country 
churches  and  on  the  morals  of  a  community?  14.  How  do 
good  roads  affect  the  society  of  a  community? 

PROBLEM 

If  it  costs  30  cents  to  haul  one  ton  a  mile,  how  much  will 
it  cost  to  haul  5,000  pounds  of  tobacco  eight  miles? 


Appendix  of  Useful  Tables. 


APPENDIX 


858 


COMPOSITION  OF  MANURES 


Table  I 
Nitrogenous  Manure* 


Pounds  Per  Hundred. 

ARTICLE 

Nitrogen. 

Phosphoric 
Acid. 

Potash 

15H  to  16 

U       to  11    ' 

10  toll 

11  tol2^ 

6  to   6 

7  to   9 
6«to   1H 

8     to"6 

1     to   i 

11        toll 

6      to    8 
I*  to   2 

Ammonium  sulphate 

Urieii  blood,  high  grade 

Dried  fish  scrap    .   

Cottonseed- meal 

ito**' 

Tabi.l  II 
Pho*pli'it"'  Mat 


Pounds  Per  Hundred 

. 

ARTICLE 

Phosphoric  acid. 

Nitrogen. 

Available 

Insoluble 

Total. 

8.  0.  phosphate  r«>< 
Florida  phosphate  rock  .. . 

•solved  rock 

Florida  dissolved  rock 

Ground  bone 

Steamed  bone 

12  to  16 

14  to  16 

5  to   8 

6  to   9 

15  to  IB 

26  to  28 

M  to  ■ 
Ito   8 
Ito   4 

U  10  17 

M  ton 

2tO   8 

M  |o  fj 
HtoH 

M  to  H 
M  tots' 

■  to  » 

16  to  17 

2     to  8 

Dissolved  bone 

254 


ELEMENTS    OF   AGRICULTURE 


Composition  of  Manures — Continued 


Table  III 
Potassic  Manures 


ARTICLE. 

Pounds  Per  Hundred 

Potash. 

Phosphoric 
Acid. 

Lime. 

Chlorine. 

Muriate  of  potash 

50 

48  to  52 

12  to  12% 

16  to  20 

20  to  30 

2  to    8 

lto    2 

5  to    8 

"io"' 

30  to  35 
35  to  40 

3% 

45     to  48 

Sulphate  of  potash 

Kainit          

%to   V-A 
30     to  32 

Sylvanit 

42     to  46 

Cottonseed-hull  ashe* 

Wood  ashes,  unleached  . . . 

Wood  ashes,  leached 

Tobacco  steins 

7  to  9 
lto  2 
lto  IK 
3  to  5  " 

Table  IV 
Average  Composition  of  Farm  Manures 


Pounds  Per  Hundred. 

ARTICLE. 

Moisture. 

Nitrogen. 

Phosphoric 
Acid. 

Potash. 

Lime. 

Cow  manure, fresh 

Horse  manure 

Sheep  manure 

Hog  manure 

85. 3 
71.3 
64.6 
72.4 
56.0 

75.0 

0.38 
0.58 
0.83 
0.45 
1.63 

0.50 

0.16 
0.28 
0.23 
0.19 
1.54 

0.26 

0.36 
0.53 
0.67 
0.60 
0.85 

0.63 

0.31 
0.21 
0.33 
0.08 
0.24 

Mixed  stable   ma 

0.70 

APPKM'IX 


355 


STOCK  FOODS 


Taiu.i:  V 
Average  Comjwtition  <•/  Stock  Food* 


Pounds  Per  Hundred. 

NAME  OF  FOOD. 

m 

n 

m 

•c 

3 
E 

o 

ill 

2  w 

J3 

m 
< 

a 

2 

Green  Food  and  Ensilage. 
Corn  fodder 

79.8 
69.4 
76  6 

71   7 
06.1 

7"  H 

n  i 

40.  & 
0  6 

12.9 
H.l 

W  7 

M 

08.4 
11  8 

n  b 

10  6 
9.9 

15.0 

9  1 

11  V 

u  i 

85 
10.5 

1.8 

1  | 

2  0 
1.1 

4  1 
4  4 

1   7 

8.8 

8  v 
6  9 

1«>   1 

16  6 
8.4 

11 
19 

10.6 
11.8 
19  4 
11  | 
94.2 
19.4 

9  2 
86 
9  0 

16  6 
48.8 

4   4 

0.6 

16 
0.6 
0.9 
1  :» 
1  1 
8  i 
0.8 

1    1 

:<  :\ 

2.8 

11 

0.2 

6.4 

I  1 

19.6 

8  8 
8.6 

6.8 
4  0 
4  0 
18.5 
J.2 

12  2 

6  8 
17  :i 
17  « 
18.6 

71 
11.0 

81.5 
47  9 

88.1 
42  9 

48.4 

«  1 

26.8 

69.6 
69  7 
69  8 

28.9 

64.8 
62.1 
68.9 
60.4 
■  | 
86.8 

5.0 
8.8 
11  6 
59 
1  1 
8.1 
4  8 
6.0 

19  7 

29.0 

M  8 
88  1 

88.1 

l   1 

1   1 

I  1 

1  1 
22.6 

1.9 
6.6 

n  ; 

v»  <• 
48.8 

1.2 

N>ri;hum  fodder  

1  8 

Bermuda  Brass 

Kentucky  Diuegrass 

K.-«i  elon  r                              

Cow  pea  vines 

Corn  ensilage 

Hay  and  Other  Dry  Coarse  Fvtlder. 

Corn  stover. 

Bermuda  hay 

1  8 

I   1 

1   7 
1  4 

8  4 

Timothy  hav 

Hay  of  mtx»d  grasses  

Clover  hay.. 

Cowpea  vine  hay                        

4  4 

6  5 
6  2 

Oat  straw 

Wheat  straw 

Root  Crops. 
Turnips. 
Sweet  potatoes 

Grain  Crops  and  Other  | 

Corn                                               

Oats. 

Barley 

Wheat. 

Cowpeas. 

Cottonseed  . 

Mill  Produets. 

■    •  I 
i  um  and  cob  meal 
ran 

5  1 
1.1 

0.8 

1   1 

8  0 

1   8 
8  1 
4    7 

1    1 

,\ 

t  a 

nseed-hulls 

2  7 

256 


ELEMENTS   OF  AGRICULTURE 


Stock  Foods— Continued 


Table  VI 
Per  Cent  of  Nutrients  Digestible  in  Stock  Foods 


NAME  OF  FOOD. 


Digestible  Nutrients. 

1 

oj 
* 

S3 

a>  a)  2 

ti 

b 

A 

1 
ft 

g 

t£<V   g 

66 

53 

76 

74 

52 

67 

46 

74 

74 

59 

74 

79 

74 

71 

80 

71 

70 

63 

73 

76 

66 

67 

65 

78 

53 

76 

74 

59 

84 

57 

64 

52 

85 

69 

62 

60 

45 

62 

61 

67 

57 

48 

57 

68 

52 

58 

58 

48 

59 

60 

61 

62 

62 

69 

49 

59 

65 

50 

71 

43 

48 

30 

33 

44 

54 

43 

11 

31 

38 

52 

93 

90 

98 

97 

100 

85 

61 

90 

91 

76 

86 

93 

58 

70 

78 

83 

76 

20 

86 

70 

89 

92 

50 

87 

83 

55 

94 

26 

66 

68 

87 

50 

76 

88 

60 

92 

93 

79 

52 

84 

88 

45 

61 

79 

68 

69 

22 

79 

82 

85 

85 

36 

76 

88 

93 

64 

32 

a 

6 

79 

34 

47 

Green  Food  and  Ensilage. 

Corn  fodder 

Sorghum  fodder 

Rye  fodder 

Pasture  grass 

Clover 

Cowpea  vines 

Corn  ensilage.  

Hay  and  Other  Dry  Coarse  Fodder 

Corn  stover 

Timothy  hay 

Hay  of  mixed  grasses 

Clover  hay 

Cowpea  vine  hay 

Oat  straw 

Wheat  straw 

Soot  Crops. 

Turnips 

Potatoes 

Qrain  Crops  and  Other  Seed. 

Corn 

Oats 

Barley 

Pea  meal 

Cottonseed 

Mill  Products. 

Corn  meal 

Corn  and  cob  meal 

Wheat  bran 

Wheat  middlings 

Cottonseed-meal 

Cottonseed-hulls 


A  PI' KM  H  X 


257 


Stock  Foods— Continued 


Table  VII 


Average  of  Digest! Ms  Xutrients  and  Fertilizing  Constitumts 
in  Stock  Foods 


NAMK  OF  FOOD. 


«  o 


DIGESTIBLE 

Nutrients  in  100 
Pounds. 


2* 


Fertilizing 
Constituent-  in 

1INI    POI 


H 


Oreen  Food  and  Ensilage. 

Corn  fodder 

Sortfhum  fodder 

Rye  fodder 

Kentucky  bluegrass 

Red  clover 

Cowpea  Tines 

Corn  ensilage 

Bay  and  Other  Dry  Coarse 
Fodders. 

Corn  stover 

rimothy  hay 

Hav  of  mixed  grasses 

Red  clover 

C<> w pea  vine  hay 

Oat  straw 

Wheat  straw 

Root  Crops. 

Turnips 

Potatoes 

Grain  and  Otner  Seed. 

Corn 

Oats  

Barl.  

Cowpeas  .    . 
I 

Mill  Products. 

Corn  meal 

.••nd  cob  meal 

IV  lira  t  bran  

Wheat  middlings 

C«>ttonseedmeal 
i         useed  hull* 


20.7 
80  0 
28  4 
84  8 
29 .2 
18  4 
20.11 


H  I 

80  8 
871 
84.7 
U  I 

00.4 


8.6 
81.6 


88.1 
88.0 
Ml  1 
ST  | 
80.1 


■  o 

84  8 

bK    1 
h7    V 

81.6 

m  i 


1.0 
0.7 
1.1 
8  0 
2.8 
1.8 
0.8 


1  7 

2  8 
6.8 
7.6 

10.8 
12 
0.4 


1.0 
1.2 


8  0 

8  7 
20  0 
18.2 


6.6 
4  4 

U  I 

12  8 

88.1 

(i  | 


0  4 
1.2 
0  4 
0.8 
0.7 
0  2 
0.7 


0.7 
1  4 

1  I 

2  0 
1  1 
0  8 
0.4 


0  2 


4  6 
4  2 
16 
0  8 
16.V 


8.6 
2  8 

8  4 

12  6 
1  7 


11.6 
17.6 
14  1 
18.8 
14  8 
8.7 
11.8 


82.4 
48.4 
40  8 
88.4 

,:«i  Q 
:<s  i 
H  I 


6.1 
24.1 


■  | 
47  8 
66  6 
H  I 

2V   1 


H  s 

00  0 

M  I 

.VI  t 

M  v 


0.80 

0.15 

0.80 

0.00 

0.68 

0.25 

6!m 

0  15 

0.27 

0  10 

0.28 

0.10 

1.10 

0.28 

1.00 

0.60 

1  40 

0  27 

2  00 

0  88 

2  66 

0.62 

0  46 

0.28 

0.00 

0.22 

0.18 

0.08 

0.24 

0.08 

1.68 

0  57 

1.66 

0  68 

1.61 

0  78 

8.87 

082 

8.10 

1  08 

168 

0  63 

IH 

0  57 

2.67 

2  88 

2.68 

086 

6.80 

300 

0.68 

0  26 

0  80 
0  26 
0.70 

040 
0  80 
0  37 


0S4 
0.87 


087 
0.48 

0  88 

1  ov 


0  40 

0  47 

1  11 
I  ■ 

1  60 

i  H 


258 


ELEMENTS   OF   AGRICULTURE 


Stock  Foods— Continued 


Table  VIII 
Pounds  of  Food  Required  Per  Day  for  1,000  Pounds  Live  Weight 


KIND  OF  ANIMAL. 


Digestible 
Nutrients. 


si 


Oxen  at  rest  in  stall 

Oxen  at  moderate  work 

Fattening  cattle 

Milcti  cows 

Sheep,  wool  growing 

Sheep,  fattening 

Horses,  moderate  work 

Horses,  hard  work 

Swine,  fattening 

Growing  Cattle. 

.     •  .  Average  live 

£&SL  wt.  per  head, 
months.  FLbg. 

2-3 .150 

8-6  300 

6-12  500 

12-18 700 

18-24 850 


0.7 
2.0 
2.7 
2.5 
1.5 
3.0 
1.8 
2.5 
4.0 


4.0 
3.0 
2.5 
2.0 
15 


0.1 
0.5 
0.6 
0.5 
0.3 
0.6 
0.6 
0.8 
0.5 


2:0 
1.0 
0.6 
0.4 
0.3 


8.0 
11.5 
15.0 
12.0 
11.0 
15.0 
11.0 
13.3 
24.0 


13.8 
13.5 
13.5 
13.0 
12.0 


1:11.8 

l:  6.5 

1:  6.1 

1:  5.3 

1:  7.8 

l:  £.5 

l:  6.9 

1:  6.0 

1:  6.3 


1:  4.7 
1:  5.3 
1:  6.0 
1:  70 

l:  8.5 


AITINI'Iv 


259 


Stock  Foods— Continued 


Table  IX 


Legal  Weights  of  drain,  Seed,  Etc.— Pounds  Per  Bushel  Required 
by  Ijaw  or  Custom 


STATES. 


3 

a 

? 

*►. 

c 

E 

« 

* 

New  York 

New  Jersey  ... 
Pennsylvania. 

Delaware 

Maryland 

Dts.  of  Columbia 
Virginia 
West  VI  nit  ii  la    . 
North  Carolina. 
South  Carolina. 
(;por*ia  ......... 

Florida 

Alabama .  . 

Mississippi 

I/oulsiana 

Texas 

Arkansas 

Tennessee 

Kentucky 


48 

02 

48 

47 

03 

47 

02 

48 

00 

48 

00 

48 

48 

00 

47 

48 

00 

47 

00 

48 

00 

48 

00 

48 

«o 

48 

flO 

47 

00 

18 


Note.— Tables  I  to  VIII,  are  compiled  from  data  published  In  the  Year 
books  of  the  U.  8.  Dept.  Agr.,and  from  other  sources. 


INDEX 


Page. 

Acid   phosphate   Ml 

lis    Ill 

n   of  soils    l-l 

Agriculture,    Primary  object  of 1M 

iniM.sltlou    «»f    24 

nt    Of    23 

In   the  soil    124,  120 

Necessary    tor   un-mlnatioii    33 

Necessary  for  (TOD  log  root!  61 

Solids    In    30 

Albuminoids     47 

Aluminum    81 

Ammonia,  Definition   of    

In   tin-   air    

Loss   of,    from    mnnure 131 

Sulpha!.-    Of    IM 

Animals,  Care    of    100-194 

r..mposltlon  of   181-185 

d  of ist-iae,  -M  m 

Growth   of    186,  187 

H..u    t..  flood    188,  105-107 

Pasturing    l> 

Animals   .  .• 

Apatite    138 

Apparatus   for   germinating    s.-.d 

Ash.   Estimation   of   200 

Ashes,  Of  animal  bofttel   184 

Of   plants   46,60 

Of  w  Ml 

Atmosphere.    8ee  Air. 

Bacteria,  In  air  81 

In    maniii 

In    «A 

Boueyard  manure   .  .N....  120 

Bean    plant    

Biennials    ...  ....    88 

(261) 


262  Elements  of  agriculture 

Page. 

Birds,  And  cultivated  crops 230,  231 

Destruction   of    218 

Harm    by    230 

Insectivorous (. .; .  .222-227 

Seed-eating    ; , ; 228-281 

Value   of    :...; ,...; J219-221 

Attd   weeds    228,  229 

Birds  of  Prey,  Harm  by 233 

Prejudice   against    232,  233 

Value  of  234 

Blood,    Dried   .;; „  * J35 

Bone  phosphate 50,  84,  141 

Bones    : 135,  181 

Breathing ;, uu 

Calcium,  Properties  of ; j ;.  52 

In  soils   ;.*..: ;* ; ;. 84 

Phosphate    i ;..; s ;.  50 

Carbohydrates     ;...!,; : 48 

Carbon,  Properties  of ...;.....:..  26 

Sources    Of,    in    plahtS ;: :  ;.......;..  .;      90 

Carbon  Dioxide,  Formation  of ; ; ;...;.    26 

In  the  air  ;..., 28,  60 

Cellulose    ; ;  ;  . . . . 48 

Cereals    .............'. ; . . . ; ; 157 

Chile  saltpetre 133 

Chlorophyll   43,  58,   65 

Chlorine     51 

Clay    80 

Clouds 12 

Clovers    96,    157,  166-168 

Composting    131 

Compounds,  Definition    of    24 

Manufactured   in   plant *...    64 

Cendensation    11 

Corn,  Meaning  of  word 158 

Germination  of  seed  36 

Roots  of  plant   40 

As   a   crop 159 

Cotton,  As  a  crop 174 

Cottonseed-meal   134 

Cows,   Treatment  of 192 

Cowpeas   146,    167 

Crops,  Cereals Iff! 

Classification  of  157 

Cultivation  of  125 

Fodder   160,   164 

Cultivation   117 


im.ix  263 


Pfef* 

DentrifiViitlon    IH 

PtierCi   101 

Dew    20 

Digestion,  Coefficients  of  206 

::iiltlon  of    108 

Experiments    

Drains    11!) 

Drainage   118 

Dried  Blood.     See  Blood. 
ffer. 

Dry  Matter,  Of  animals  182 

Of  plants  46 

Dust    80 

Kletn.-nts    24 

Embryo    

■MlUll    160-163 

Erosion     18 

Evaporation,  Definition  of  11 

As  a  temperature  regulator 21 

■nfMt   103 

'  Fall  plowing  124 

Farming.    QtMnl  ami  ■prclll IH 

Fat.    Crmle.    Estimation    of L'in) 

Feeding    standards     fWHIl 

208 

Feldspars    84 

Fertllit>   >•(  solli  100 

Fertilizers.  Definition   <-f    HI 

Manufacture   of    140 

Nltrog.-m.ns     133 

ptetk  ...  137 

4c  i:t*» 

\;ii.Mii..„    <>f    142*144 

FiN.r.    rr,i(l.-.     IStimation    of 201 

Film    BClltlW    8© 

Flub  m  136 

;*,  Classification   ..f    .  160 

Don    ...  164 

■Mm  <-r  160 

.  Dry,   coarse    .  164 

Green    . .  160 

Full-  I  164 

12 


Forests,  As  a  cr< 

Destruction  of 
Value  of 


264  ELEMENTS    OF   AGRICULTURE 

Page. 

Free  water  in  soils  90 

Frost    29 

Gases 14 

Germination 37,  153 

Glaciers   73 

Grain   crops    157-159 

Grasses    : . . .  165 

Green  Fodder.     See  Fodder. 

Manure  146 

Ground  water 91 

Gypsum 129 

Hail   12 

Hard  pan   122 

Hard  water   20 

Hawks.     See  Birds  of  Prey. 

Hay,  Classes  of  165 

Curing    166 

Of   grasses 165 

Of  legumes    166-168 

Time  for  cutting .166,  168 

Heat    10 

Herbivorous  animals 196 

Humates   114 

Humus 70,  79,  107,  111,  113,  114,  115 

Hydrogen    , 26 

Indian  Com.     See  Corn. 

Inorganic   matter  of   soils 70,  79 

Insects,  Damage  by  222 

Eaten  by  birds 223  225 

Irish  potato » 173 

Iron,  Properties  of   52 

In   soils    85 

Iron   and   aluminum   phosphate 84 

Irrigation 118,   119 

Kainit    136 

Kaolin    81 

Land   67 

Land  plaster 1-9 

Leaching    19 

Leaves    42 

Leguminosae    Plants,    Fixation    of    nitrogen    by 96 

For  hay  166 

For  manure 146 

Life  in  the  soil  115 


i i dex  265 

Light,    Effect   on   plant 16 

l.lmr.    l.-riiiatioii    c.f    62 

In  soils 85,  86,  114.   115 

Limestone  soils 85 

Li. tui. I.    14 

Loamy  soils   74 

Lye    51,   52 

Magnesium 52 

Manganese    52 

Manures,   Barnvanl     129 

Classification   of    128 

Definition  of   128 

( otu-rnl    145 

•  n   Ml 

Natural     128 

Purpose  of   145 

8peelal    14.-,.    11*.    14'.* 

Stabh-    130 

Use  of   145-148 

Marl    1^8 

Meteors    ID 

"logy    31 

Mineral  matter  of  plants  4G 

Composition  of  50 

Sources  of  57,  63 

Mineral  matt.-r  of  soils  68,  71,  79 

Loss  of,   by   cultivation 110-115 

Mississippi   Klv.-r   22,  239 

Mist     

Mixtures    25 

Moisture,  In  nir   29 

In  plants 4.".,  65,  56,  57,  63 

||  polk   78,  83,  88-93.  100-105,  118-180,   12  1 

Effort    on    tnnprratim-s    I 

Estimation    of     200 

Mold     U 

Muek    B6 

Mul.h   104 

Muriate  of  Potash.     See  Potash. 

Mb-  sttVOf  M 

Nitrate  of  soda    .  M 

Mtrltbntlon    ...  95 

Nitrogen,  Free  extract   201 

Properties  of    .28 

In  the  air  24,  26 

In  plants  46,47,57,62 


266 


ELEMENTS    OF   AGRICULTURE 


Page. 

Nitrogen  in  Soils,  Importance  of   94 

Sources  of 94,  98,   106 

Forms  of   98 

Necessity  of 106 

Loss  of 106,  108 

Nitrogenous  Matter.     See  Protein! 

Non-Nitrogenous  Matter,  In  Plants  48 

In   animals    184 

Estimation  of 201 

Nutrients .'. 202 

Nutritive  ratio 209 

Oats,  As  a  crop  157,  158 

Roots  of .... 41 

Organic  matter  of  plants 46 

Of  soils. 70,  78,  79,  86,  94,  95,  98,  106,  107 

Organs  of  plants   , 38 

Owls.     See  Birds  of  Prey. 

Oxidation 25 

Oxygen  in  air   24,  25 

Properties   of   .......:...    25 

In  soils 61,   124 

Pastures,  Classes  of   168 

Permanent    168,   169 

Temporary , 169,   170 

Peaty  soils  74 

Perennials  33 

Phosphates,  In  plants .50,  58 

In  soils 83,  110-113 

In  fertilizers     133,  138-143 

Phosphate  Rock,  Where  found   138 

Appearance  of 139 

Composition  of 139 

Phosphoric  acid   51 

Phosphorus,  Properties  of  50 

In  soils 83,  110 

In  fertilizers  133 

In  phosphate  rock    139 

Plants,  Classes  of  33 

Seed  of 33,  34,  35 

Parts  of 38-43 

Composition  of  45-53 

Food  of   55-62 

Growth  of 63-66 

Plant  food    58 

Plowing   122,   125 


1SDEX  267 

Potassium.  Properties  of   51 

In  plants   51,  58 

Ii  poili  H  lit.  i" 

In  fertilizers  188,   134   Ifl 

Protein,   In  plains   40,  47.  C5 

Propertica  <»f  W 

In   animals 

in  fooda  Mi 

Quartz    

Quick    llnm    52 

Ha. Ilatlon     If 

Radish    plains H 

Italn,      Formation    i.f     

Work  «.r  Ifrftl 

A  robber   *-'" 

Ratio,    Nutration.      See    Nutritive. 

Rations   f,.r  Animals 

Coinpnunilinu'     BOO  -\2 

-,'hin^   MM,   90S 

Rice  a«  a  crop  I ~>~ 

Roads,   Interest    in    243 

Formation  of   'JIM 

Of  ,|irt    Ml 

'ion   of    I'll 

Of  Mom-    Ml 

Ma.a.lnm      'J  LI 

'IYIfonI   , KM 

ratal  Ml 

Cost  of  hauling  over   MB 

81 

Root  crops  172 

Koot      1:  

Roots    

Rotation  of  rrops    177 

Benefits   of    177  17:» 

Example  of  17!»,  180 

Salsify    89 

Salt.   In  the  soil  19 

Not  a  food  199 

Band  80 

Rap    05 

Sediment    .  ...     is 

Seed 

Sprouting    of    .14  .17 

'.MRS 

Selection   of    

Purity    of    


268  ELEMENTS    OP  AGKICULTUEE 

Pag6» 

Seed,  Germination    tests    of 153 

Necessity  for  testing 153 

Adulteration  of 153 

Cost  of 154 

Deterioration   of 155 

Seed  leaves 35 

Silage.     See  Ensilage. 

Silica    80 

Silicates 51,  84 

Silicon    51 

Silo   160 

Snow  12 

Sod 168 

Sodium  51 

Carbonate  of  52 

Soft  Water.     See  Water. 

Soiling   160 

Soils,  Definition  of   67 

Formation  of 68-70 

Organic   matter   in 70,   78,   79 

Transported   .' 72 

In  place ' 73 

Classified  73-76 

Sandy     74 

Clay    74 

Loam 74 

Light    74 

Heavy 74 

Weight   of    ',5 

Warm  75 

Cold 75 

Color   of 76 

Water  in   78,  88-93 

Inorganic  matter  in   79 

Plant  food   in 83 

Phosphorus  In   : S3,  110-113 

Potash  in  84,  113,  114 

Calcium  In   84 

Iron   in    85 

Analyses  of  86 

Deep 92 

Shallow    92 

Nitrogen  in 94-98 

Lime  in 114 

Loss  of  water  In 100-104 

Loss  of  fertility  100-116 

Source  of  water  In 102 

Surface  evaporation  from  103 

Loss  of  nitrogen  In 106-108 


INDEX  M9 

Plft, 

i.otw  of  mineral  matter  in   110*134 

Lift  In   116 

Culthatimi   of    117  OB 

Air    In    ]M 

Restoration   of    145-148 

Soil, is.  Definition  of   II 

In  the  air  30 

8ojr  bean  97 

Springs 91 

Stable  Manure.     See  Mnnun- 

Hi 

Starch   64 

Stassfurt  K'.r. 

St.:.  in    10 



Stock  terming isi 

Stock   Foods    198  MM 

<"ii,|M.siil t    200-202 

of _'lf..   m 

• -tlblllty    of    LiU  J" 7 

Selection  of   214-217 

Volume  of   _1» 

Stomata    56 

Storoarhs  of  animals   I'll.   Ufl 

-     67 

sti:.u  m 

tfA  IrrlKntlon    HO 

Snl.soll    87 

Sugar  in    plants    48 

In    animals    184 

Sulphur    47 

Sunllcht      !» 

Swamps     lis 

poUtoea  10,  i~:t 

syivinh  iaa 

Tankage    ...  IM 



illK     ,   Iff 

Thermometers     |  \ 

Tobacco  . . .  174 

Transportation    .  H 

«rop*    1 7  J  17  1 

Tul.i-n  l.s 90,  97 

1'n.l.  r  drains   

Veins  of  leaves  t  : 

Velocity  of  heat  and  light. 

Ventilation  of  stables  .  190 


270  ELEMENTS  OF   AGRICULTURE 

Page. 

Volatile  matter  of  plants 46 

Of  animals    183 

Water 26 

Vapor   of 29 

In  plants  55,  56,  63 

Mechanical  action  of,  on  soils 68 

Chemical  action  of,  on  soils 69 

Transports   soils    72 

In  soils   75,  78,  88,  93,  118,  120 

Lack  of,  in  soils 100-105 

In  animal  bodies   182 

For  stock  195 

Water  table   91 

Weeds,  Destruction  of  228 

Wells 91 

Wheat 157-159 

Winds 15 

Wood   ashes    129 

Wood's  mold  .,,.,,,, , , , 129 


OF  THE     ^ 

UNIVERSITY 

OF 


YB  45439 


Hfr, 


y 


